Organic semiconducting polymers

ABSTRACT

The invention relates to novel organic semiconducting polymers containing one or more monomers derived from s-indacene fused symmetrically on each terminus with dithieno[3,2-b;2′,3′-d]thiophene (IDDTT), cyclopenta[2,1-b;3,4-b′]dithiophene (IDCDT), or derivatives thereof, to methods for their preparation and educts or intermediates used therein, to polymer blends, mixtures and formulations containing them, to the use of the polymers, polymer blends, mixtures and formulations as semiconductors in organic electronic (OE) devices, especially in organic photovoltaic (OPV) devices and organic photodetectors (OPD), and to OE, OPV and OPD devices comprising these polymers, polymer blends, mixtures or formulations.

TECHNICAL FIELD

The invention relates to novel organic semiconducting polymerscontaining one or more monomers derived from s-indacene fusedsymmetrically on each terminus with dithieno[3,2-b;2′,3′-d]thiophene(IDDTT), cyclopenta[2,1-b;3,4-b]dithiophene (IDCDT), or derivativesthereof, to methods for their preparation and educts or intermediatesused therein, to polymer blends, mixtures and formulations containingthem, to the use of the polymers, polymer blends, mixtures andformulations as semiconductors in organic electronic (OE) devices,especially in organic photovoltaic (OPV) devices and organicphotodetectors (OPD), and to OE, OPV and OPD devices comprising thesepolymers, polymer blends, mixtures or formulations.

BACKGROUND

Organic semiconducting (OSC) materials are receiving growing interestmostly due to their rapid development in the recent years and thelucrative commercial prospects of organic electronics.

One particular area of importance is organic photovoltaics (OPV).Conjugated polymers have found use in OPVs as they allow devices to bemanufactured by solution-processing techniques such as spin casting, dipcoating or ink jet printing. Solution processing can be carried outcheaper and on a larger scale compared to the evaporative techniquesused to make inorganic thin film devices. Currently, polymer basedphotovoltaic devices are achieving efficiencies above 8%.

In order to obtain ideal solution-processible OSC molecules two basicfeatures are essential, firstly a rigid π-conjugated core unit to formthe backbone, and secondly a suitable functionality attached to thearomatic core unit in the OSC backbone. The former extends π-π overlaps,defines the primary energy levels of the highest occupied and lowestunoccupied molecular orbitals (HOMO and LUMO), enables both chargeinjection and transport, and facilitates optical absorption. The latterfurther fine-tunes the energy levels and enables solubility and henceprocessability of the materials as well as π-π interactions of themolecular backbones in the solid state.

A high degree of molecular planarity reduces the energetic disorder ofOSC backbones and accordingly enhances charge carrier mobilities.Linearly fusing aromatic rings is an efficient way of achieving maximumplanarity with extended π-π conjugation of OSC molecules. Accordingly,most of the known polymeric OSCs with high charge carrier mobilities aregenerally composed of fused ring aromatic systems and aresemicrystalline in their solid states. On the other hand, such fusedaromatic ring systems are often difficult to synthesize, and do alsooften show poor solubility in organic solvents, which renders theirprocessing as thin films for use in OE devices more difficult. Also, theOSC materials disclosed in prior art still leave room for furtherimprovement regarding their electronic properties.

Thus there is still a need for organic semiconducting (OSC) polymerswhich are easy to synthesize, especially by methods suitable for massproduction, show good structural organization and film-formingproperties, exhibit good electronic properties, especially a high chargecarrier mobility, a good processibility, especially a high solubility inorganic solvents, and high stability in air. Especially for use in OPVcells, there is a need for OSC materials having a low bandgap, whichenable improved light harvesting by the photoactive layer and can leadto higher cell efficiencies, compared to the polymers from prior art.

It was an aim of the present invention to provide compounds for use asorganic semiconducting materials that are easy to synthesize, especiallyby methods suitable for mass production, and do especially show goodprocessibility, high stability, good solubility in organic solvents,high charge carrier mobility, and a low bandgap. Another aim of theinvention was to extend the pool of OSC materials available to theexpert. Other aims of the present invention are immediately evident tothe expert from the following detailed description.

The inventors of the present invention have found that one or more ofthe above aims can be achieved by providing conjugated polymerscontaining one or more monomers derived from s-indacene that is fusedsymmetrically in each terminus with dithieno[3,2-b;2′,3′-d]thiophene(IDDTT), cyclopenta[2,1-b;3,4-b]dithiophene (IDCDT), or derivativesthereof. This was made possible by overcoming the synthetic difficultiesfaced when trying to make large fused ring systems. Surprisingly it wasalso found that these enlarged fused ring systems, and the polymerscontaining them, still show sufficient solubility in organic solvents,which can also be further improved by introducing alkyl or alkylidenesubstituents onto the indacene unit. Both the homo- and co-polymers canbe prepared through known transition metal catalysed polycondensationreactions. It was also found that the polymers according to the presentinvention have improved planarity, leading to improved the chargemobilities. As a result the polymers of the present invention were foundto be attractive candidates for solution processable organicsemiconductors both for use in transistor applications and photovoltaicapplications. By further variation of the substituents on the fusedaromatic ring system, the solubility and electronic properties of themonomers and polymers can be further optimised.

Conjugated polymers that contain in their backbone highly fused systemsas disclosed in the present invention and as claimed hereinafter havenot been reported in prior art so far. GB 2 472 413 A discloses smallmolecule materials of the structure I as shown below. However, nopolymers have been reported so far.

US 2011/166362 A1 discloses small molecules containing linearly fusedpolycyclic aromatic backbones as in structure II below, where one of thefour groups of W, X, Y and Z has to be a substituted phenylamino group.Again, no polymers using these structures have been reported so far.

SUMMARY

The invention relates to conjugated polymers comprising one or morerepeating units of formula I

wherein

-   W¹ and W² are independently of each other C(R¹R²), C═C(R¹R²),    Si(R¹R²) or C═O,-   X¹ and X² are independently of each other S, C(R³R⁴), Si(R³R⁴),    C═C(R³R⁴) or C═O,-   one of T¹ and T² is S and the other is CH,-   R¹⁻⁴ independently of each other denote H, straight-chain, branched    or cyclic alkyl with 1 to 30 C atoms, in which one or more    non-adjacent CH₂ groups are optionally replaced by one or more    non-adjacent CH₂ groups are optionally replaced by —O—, —S—, —C(O)—,    —C(O)—O—, —O—C(O)—, —O—C(±)—O—, —NR⁰—, —SiR⁰R⁰⁰—, —CF₂—,    —CHR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C— in such a manner that O and/or S    atoms are not linked directly to one another, and in which one or    more H atoms are optionally replaced by F, Cl, Br, I or CN, or    denote aryl, heteroaryl, aryloxy or heteroaryloxy with 4 to 20 ring    atoms which is optionally substituted, preferably by one or more of    the aforementioned alkyl or cyclic alkyl groups,-   Y¹ and Y² are independently of each other H, F, Cl or CN,-   R⁰ and R⁰⁰ are independently of each other H or optionally    substituted C₁₋₄₀ carbyl or hydrocarbyl, and preferably denote H or    alkyl with 1 to 12 C-atoms.

The invention further relates to a formulation comprising one or morepolymers comprising a unit of formula I and one or more solvents,preferably selected from organic solvents.

The invention further relates to the use of units of formula I aselectron donor units in semiconducting polymers.

The invention further relates to conjugated polymers comprising one ormore repeating units of formula I and/or one or more groups selectedfrom aryl and heteroaryl groups that are optionally substituted, andwherein at least one repeating unit in the polymer is a unit of formulaI.

The invention further relates to monomers containing a unit of formula Iand further containing one or more reactive groups which can be reactedto form a conjugated polymer as described above and below.

The invention further relates to semiconducting polymers comprising oneor more units of formula I as electron donor units, and preferablyfurther comprising one or more units having electron acceptorproperties.

The invention further relates to the use of the polymers according tothe present invention as electron donor or p-type semiconductor.

The invention further relates to the use of the polymers according tothe present invention as electron donor component in a semiconductingmaterial, formulation, polymer blend, device or component of a device.

The invention further relates to a semiconducting material, formulation,polymer blend, device or component of a device comprising a polymeraccording to the present invention as electron donor component, andpreferably further comprising one or more compounds or polymers havingelectron acceptor properties.

The invention further relates to a mixture or polymer blend comprisingone or more polymers according to the present invention and one or moreadditional compounds which are preferably selected from compounds havingone or more of semiconducting, charge transport, hole or electrontransport, hole or electron blocking, electrically conducting,photoconducting or light emitting properties.

The invention further relates to a mixture or polymer blend as describedabove and below, which comprises one or more polymers of the presentinvention and one or more n-type organic semiconductor compounds,preferably selected from fullerenes or substituted fullerenes.

The invention further relates to a formulation comprising one or morepolymers, formulations, mixtures or polymer blends according to thepresent invention and optionally one or more solvents, preferablyselected from organic solvents.

The invention further relates to the use of a polymer, formulation,mixture or polymer blend of the present invention as charge transport,semiconducting, electrically conducting, photoconducting or lightemitting material, or in an optical, electrooptical, electronic,electroluminescent or photoluminescent device, or in a component of sucha device or in an assembly comprising such a device or component.

The invention further relates to a charge transport, semiconducting,electrically conducting, photoconducting or light emitting materialcomprising a polymer, formulation, mixture or polymer blend according tothe present invention.

The invention further relates to an optical, electrooptical, electronic,electroluminescent or photoluminescent device, or a component thereof,or an assembly comprising it, which comprises a polymer, formulation,mixture or polymer blend, or comprises a charge transport,semiconducting, electrically conducting, photoconducting or lightemitting material, according to the present invention.

The optical, electrooptical, electronic, electroluminescent andphotoluminescent devices include, without limitation, organic fieldeffect transistors (OFET), organic thin film transistors (OTFT), organiclight emitting diodes (OLED), organic light emitting transistors (OLET),organic photovoltaic devices (OPV), organic photodetectors (OPD),organic solar cells, laser diodes, Schottky diodes and photoconductors.

The components of the above devices include, without limitation, chargeinjection layers, charge transport layers, interlayers, planarisinglayers, antistatic films, polymer electrolyte membranes (PEM),conducting substrates and conducting patterns.

The assemblies comprising such devices or components include, withoutlimitation, integrated circuits (IC), radio frequency identification(RFID) tags or security markings or security devices containing them,flat panel displays or backlights thereof, electrophotographic devices,electrophotographic recording devices, organic memory devices, sensordevices, biosensors and biochips.

In addition the compounds, polymers, formulations, mixtures or polymerblends of the present invention can be used as electrode materials inbatteries and in components or devices for detecting and discriminatingDNA sequences.

DETAILED DESCRIPTION

The polymers of the present invention are easy to synthesize and exhibitadvantageous properties. They show good processability for the devicemanufacture process, high solubility in organic solvents, and areespecially suitable for large scale production using solution processingmethods. At the same time, the co-polymers derived from monomers of thepresent invention and electron donor monomers show low bandgaps, highcharge carrier mobilities, high external quantum efficiencies in BHJsolar cells, good morphology when used in p/n-type blends e.g. withfullerenes, high oxidative stability, and a long lifetime in electronicdevices, and are promising materials for organic electronic OE devices,especially for OPV devices with high power conversion efficiency.

The units of formula I are especially suitable as (electron) donor unitin both n-type and p-type semiconducting compounds, polymers orcopolymers, in particular copolymers containing both donor and acceptorunits, and for the preparation of blends of p-type and n-typesemiconductors which are suitable for use in BHJ photovoltaic devices.

The repeating units of formula I contain an enlarged system of fusedaromatic rings, which creates numerous benefits in developing novel highperformance OSC materials. Firstly, a large number of fused aromaticrings along the long axis of the core structure increases the overallplanarity and reduces the number of the potential twists of theconjugated molecular backbone. Elongation of the π-π structure ormonomer increases the extent of conjugation which facilitates chargetransport along the polymer backbone. Secondly, the high proportion ofsulphur atoms in the molecular backbone through the presence of fusedthiophene rings promotes more intermolecular short contacts, whichbenefits charge hopping between molecules. Thirdly, the large number offused rings leads to an increased proportion of ladder structure in theOSC polymer main chain. This forms a broader and more intense absorptionband resulting in improved solar light harvesting compared with priorart materials. Additionally but not lastly, fusing aromatic rings canmore efficiently modify the HOMO and LUMO energy levels and bandgaps ofthe target monomer structures compared with periphery substitutions.

Besides, the polymers of the present invention show the followingadvantageous properties:

-   i) IDDTT and IDCDT monomers and the resultant polymers can be    solubilised by two different synthetic protocols, namely, tetraalkyl    substitution and dialkylidene substitution. The former can be    achieved by means of reacting alkyl halides with the unsubstituted    core structure under alkaline conditions. Alternatively, this    solubilised structure can be synthesized by ring-closure of the    tetraalkylated diol intermediates, whereas the latter can be    obtained through Knoevenagel condensation with a variety of carbonyl    compounds.-   ii) Solubilised IDCDT can be facilely functionalised at the terminal    positions through e.g., halogenation with N-halosuccinimide,    elemental halogen, or through lithiation with alkyllithium and    lithium amides then reacted with a halogenation reagent, alkyl    borates, trialkylstannyl chlorides or zinc chloride. These    functionalised derivatives can be used to prepare a wide range of    new homo-polymers and co-polymers through transition metal catalysed    coupling methods such as Yamamoto reaction (Yamamoto et al., Bull.,    Chem. Soc. Jpn., 1978, 51(7), 2091; Yamamoto et al., Macromolecules,    1992, 25(4), 1214), Suzuki-Miyaura reaction (Miyaura et al., Chem.    Rev., 1995, 95, 2457) and Stille reaction (Bao et al., J. Am.,    Chem., Soc., 1995, 117(50), 12426).-   iii) The optoelectronic properties of conjugated polymers vary    significantly based upon the degree of extended conjugation between    the consecutive repeating units and the inherent electron densities    within the polymer backbones. By fusing additional aromatic rings    along the long axis of s-indacenodithiophene, the π-conjugation of    the resultant molecules and consequently the polymers can be    extended and the number of the inter-repeating unit twists in the    backbone can be further reduced. This is, in theory, one of the most    efficient ways to modify the HOMO-LUMO levels and bandgaps in    designing new semiconducting polymers.-   iv) The IDDTT and IDCDT core structures can be solubilised by both    four alkyl groups or two alkylidene groups. Compared with the    tetra-alkyl analogues, the dialkylidene substituted IDCDT-based    molecules and polymers are expected to possess a higher degree of    planarity. This is due to the sp² carbon atoms in the alkylidenes    allow the alkyl chains to take an in-plane configuration. This    configuration reduces the inter-planar separation of the π-π    backbones, and improves the degree of intermolecular π-π    interactions.-   v) Similar to the known tetraalkyl-s-indacenodithiophenes,    tetra-alkyl and dialkylidene IDDTT and IDCDTs of this invention are    also π-donor units. When co-polymerized with n-accepting monomers,    low bandgap conjugated polymers are synthesized, which are potential    candidates for use in organic photovoltaic solar cells.-   vi) By fine-tuning the LUMO levels of the π-electron accepting    units, the donor-acceptor polymers synthesized using tetra-alkyl and    dialkylidene IDDTT and IDCDTs and suitable acceptor units may    exhibit ambipolar charge transport behavior in field-effect    transistors.

The synthesis of the unit of formula I, its functional derivatives,compounds, homopolymers, and co-polymers can be achieved based onmethods that are known to the skilled person and described in theliterature, as will be further illustrated herein.

Above and below, the term “polymer” generally means a molecule of highrelative molecular mass, the structure of which essentially comprisesthe multiple repetition of units derived, actually or conceptually, frommolecules of low relative molecular mass (Pure Appl. Chem., 1996, 68,2291). The term “oligomer” generally means a molecule of intermediaterelative molecular mass, the structure of which essentially comprises asmall plurality of units derived, actually or conceptually, frommolecules of lower relative molecular mass (Pure Appl. Chem., 1996, 68,2291). In a preferred sense according to the present invention a polymermeans a compound having >1, i.e. at least 2 repeating units, preferably≧5 repeating units, and an oligomer means a compound with >1 and <10,preferably <5, repeating units.

Above and below, in a formula showing a unit or a polymer, like formulaI and its subformulae, an asterisk (“*”) denotes a linkage to anadjacent unit or group, and in case of a polymer a link to an adjacentrepeating unit or to a terminal group in the polymer chain.

The terms “repeating unit” and “monomeric unit” mean the constitutionalrepeating unit (CRU), which is the smallest constitutional unit therepetition of which constitutes a regular macromolecule, a regularoligomer molecule, a regular block or a regular chain (Pure Appl. Chem.,1996, 68, 2291).

The term “small molecule” means a monomeric compound which typicallydoes not contain a reactive group by which it can be reacted to form apolymer, and which is designated to be used in monomeric form. Incontrast thereto, the term “monomer” unless stated otherwise means amonomeric compound that carries one or more reactive functional groupsby which it can be reacted to form a polymer.

The terms “donor”/“donating” and “acceptor”/“accepting”, unless statedotherwise, mean an electron donor or electron acceptor, respectively.“Electron donor” means a chemical entity that donates electrons toanother compound or another group of atoms of a compound. “Electronacceptor” means a chemical entity that accepts electrons transferred toit from another compound or another group of atoms of a compound. (seealso U.S. Environmental Protection Agency, 2009, Glossary of technicalterms, http://www.epa.gov/oust/cat/TUMGLOSS.HTM).

The term “leaving group” means an atom or group (charged or uncharged)that becomes detached from an atom in what is considered to be theresidual or main part of the molecule taking part in a specifiedreaction (see also Pure Appl. Chem., 1994, 66, 1134).

The term “conjugated” means a compound containing mainly C atoms withsp²-hybridisation (or optionally also sp-hybridisation), which may alsobe replaced by hetero atoms. In the simplest case this is for example acompound with alternating C—C single and double (or triple) bonds, butdoes also include compounds with units like 1,4-phenylene. “Mainly”means in this connection that a compound with naturally (spontaneously)occurring defects, which may lead to interruption of the conjugation, isstill regarded as a conjugated compound.

Unless stated otherwise, the molecular weight is given as the numberaverage molecular weight M_(n) or weight average molecular weight M_(W),which is determined by gel permeation chromatography (GPC) againstpolystyrene standards in eluent solvents such as tetrahydrofuran,trichloromethane (TCM, chloroform), chlorobenzene or1,2,4-trichloro-benzene. Unless stated otherwise, 1,2,4-trichlorobenzeneis used as solvent. The degree of polymerization, also referred to astotal number of repeating units, n, means the number average degree ofpolymerization given as n=M_(n)/M_(U), wherein M_(n) is the numberaverage molecular weight and M_(u) is the molecular weight of the singlerepeating unit, see J. M. G. Cowie, Polymers: Chemistry & Physics ofModern Materials, Blackie, Glasgow, 1991.

The term “carbyl group” as used above and below denotes any monovalentor multivalent organic radical moiety which comprises at least onecarbon atom either without any non-carbon atoms (like for example—C≡C—), or optionally combined with at least one non-carbon atom such asN, O, S, P, Si, Se, As, Te or Ge (for example carbonyl etc.). The term“hydrocarbyl group” denotes a carbyl group that does additionallycontain one or more H atoms and optionally contains one or more heteroatoms like for example N, O, S, P, Si, Se, As, Te or Ge.

The term “hetero atom” means an atom in an organic compound that is nota H- or C-atom, and preferably means N, O, S, P, Si, Se, As, Te or Ge.

A carbyl or hydrocarbyl group comprising a chain of 3 or more C atomsmay be straight-chain, branched and/or cyclic, including spiro and/orfused rings.

Preferred carbyl and hydrocarbyl groups include alkyl, alkoxy,alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy,each of which is optionally substituted and has 1 to 40, preferably 1 to25, very preferably 1 to 18 C atoms, furthermore optionally substitutedaryl or aryloxy having 6 to 40, preferably 6 to 25 C atoms, furthermorealkylaryloxy, arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy andaryloxycarbonyloxy, each of which is optionally substituted and has 6 to40, preferably 7 to 40 C atoms, wherein all these groups do optionallycontain one or more hetero atoms, preferably selected from N, O, S, P,Si, Se, As, Te and Ge.

The carbyl or hydrocarbyl group may be a saturated or unsaturatedacyclic group, or a saturated or unsaturated cyclic group. Unsaturatedacyclic or cyclic groups are preferred, especially aryl, alkenyl andalkynyl groups (especially ethynyl). Where the C₁-C₄₀ carbyl orhydrocarbyl group is acyclic, the group may be straight-chain orbranched. The C₁-C₄₀ carbyl or hydrocarbyl group includes for example: aC₁-C₄₀ alkyl group, a C₁-C₄₀ fluoroalkyl group, a C₁-C₄₀ alkoxy oroxaalkyl group, a C₂-C₄₀ alkenyl group, a C₂-C₄₀ alkynyl group, a C₃-C₄₀allyl group, a C₄-C₄₀ alkyldienyl group, a C₄-C₄₀ polyenyl group, aC₂-C₄₀ ketone group, a C₂-C₄₀ ester group, a C₆-C₁₈ aryl group, a C₆-C₄₀alkylaryl group, a C₆-C₄₀ arylalkyl group, a C₄-C₄₀ cycloalkyl group, aC₄-C₄₀ cycloalkenyl group, and the like. Preferred among the foregoinggroups are a C₁-C₂₀ alkyl group, a C₁-C₂₀ fluoroalkyl group, a C₂-C₂₀alkenyl group, a C₂-C₂₀ alkynyl group, a C₃-C₂₀ allyl group, a C₄-C₂₀alkyldienyl group, a C₂-C₂₀ ketone group, a C₂-C₂₀ ester group, a C₆-C₁₂aryl group, and a C₄-C₂₀ polyenyl group, respectively. Also included arecombinations of groups having carbon atoms and groups having heteroatoms, like e.g. an alkynyl group, preferably ethynyl, that issubstituted with a silyl group, preferably a trialkylsilyl group.

Aryl and heteroaryl preferably denote a mono-, bi- or tricyclic aromaticor heteroaromatic group with 4 to 30 ring C atoms that may also comprisecondensed rings and is optionally substituted with one or more groups L,

wherein L is selected from halogen, —CN, —NC, —NCO, —NCS, —OCN, —SCN,—C(═O)NR⁰R⁰⁰, —C(═O)X⁰, —C(═O)R⁰, —NH₂, —NR⁰R⁰⁰, —SH, —SR⁰, —SO₃H,—SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, P-Sp-, optionally substituted silyl, orcarbyl or hydrocarbyl with 1 to 40 C atoms that is optionallysubstituted and optionally comprises one or more hetero atoms, and ispreferably alkyl, alkoxy, thiaalkyl, alkylcarbonyl, alkoxycarbonyl oralkoxycarbonyloxy with 1 to 20 C atoms that is optionally fluorinated,and R⁰, R⁰⁰, X⁰, P and Sp have the meanings given above and below.

Very preferred substituents L are selected from halogen, most preferablyF, or alkyl, alkoxy, oxaalkyl, thioalkyl, fluoroalkyl and fluoroalkoxywith 1 to 12 C atoms or alkenyl, alkynyl with 2 to 12 C atoms.

Especially preferred aryl and heteroaryl groups are phenyl in which, inaddition, one or more CH groups may be replaced by N, naphthalene,thiophene, selenophene, thienothiophene, dithienothiophene, fluorene andoxazole, all of which can be unsubstituted, mono- or polysubstitutedwith L as defined above. Very preferred rings are selected from pyrrole,preferably N-pyrrole, furan, pyridine, preferably 2- or 3-pyridine,pyrimidine, pyridazine, pyrazine, triazole, tetrazole, pyrazole,imidazole, isothiazole, thiazole, thiadiazole, isoxazole, oxazole,oxadiazole, thiophene preferably 2-thiophene, selenophene, preferably2-selenophene, thieno[3,2-b]thiophene, indole, isoindole, benzofuran,benzothiophene, benzodithiophene, quinole, 2-methylquinole, isoquinole,quinoxaline, quinazoline, benzotriazole, benzimidazole, benzothiazole,benzisothiazole, benzisoxazole, benzoxadiazole, benzoxazole,benzothiadiazole, all of which can be unsubstituted, mono- orpolysubstituted with L as defined above. Further examples of heteroarylgroups are those selected from the following formulae

An alkyl or alkoxy radical, i.e. where the terminal CH₂ group isreplaced by —O—, can be straight-chain or branched. It is preferablystraight-chain, has 2, 3, 4, 5, 6, 7 or 8 carbon atoms and accordinglyis preferably ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl,ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy, or octoxy,furthermore methyl, nonyl, decyl, undecyl, dodecyl, tridecyl,tetradecyl, pentadecyl, nonoxy, decoxy, undecoxy, dodecoxy, tridecoxy ortetradecoxy, for example.

An alkenyl group, wherein one or more CH₂ groups are replaced by —CH═CH—can be straight-chain or branched. It is preferably straight-chain, has2 to 10 C atoms and accordingly is preferably vinyl, prop-1-, orprop-2-enyl, but-1-, 2- or but-3-enyl, pent-1-, 2-, 3- or pent-4-enyl,hex-1-, 2-, 3-, 4- or hex-5-enyl, hept-1-, 2-, 3-, 4-, 5- orhept-6-enyl, oct-1-, 2-, 3-, 4-, 5-, 6- or oct-7-enyl, non-1-, 2-, 3-,4-, 5-, 6-, 7- or non-8-enyl, dec-1-, 2-, 3-, 4-, 5-, 6-, 7-, 8- ordec-9-enyl.

Especially preferred alkenyl groups are C₂-C₇-1E-alkenyl,C₄-C₇-3E-alkenyl, C₅-C₇-4-alkenyl, C₆-C₇-5-alkenyl and C₇-6-alkenyl, inparticular C₂-C₇-1E-alkenyl, C₄-C₇-3E-alkenyl and C₅-C₇-4-alkenyl.Examples for particularly preferred alkenyl groups are vinyl,1E-propenyl, 1E-butenyl, 1E-pentenyl, 1E-hexenyl, 1E-heptenyl,3-butenyl, 3E-pentenyl, 3E-hexenyl, 3E-heptenyl, 4-pentenyl, 4Z-hexenyl,4E-hexenyl, 4Z-heptenyl, 5-hexenyl, 6-heptenyl and the like. Groupshaving up to 5 C atoms are generally preferred.

An oxaalkyl group, i.e. where one CH₂ group is replaced by —O—, ispreferably straight-chain 2-oxapropyl (=methoxymethyl),2-(=ethoxymethyl) or 3-oxabutyl (=2-methoxyethyl), 2-, 3-, or4-oxapentyl, 2-, 3-, 4-, or 5-oxahexyl, 2-, 3-, 4-, 5-, or 6-oxaheptyl,2-, 3-, 4-, 5-, 6- or 7-oxaoctyl, 2-, 3-, 4-, 5-, 6-, 7- or 8-oxanonylor 2-, 3-, 4-, 5-, 6-, 7-, 8- or 9-oxadecyl, for example. Oxaalkyl, i.e.where one CH₂ group is replaced by —O—, is preferably straight-chain2-oxapropyl (=methoxymethyl), 2-(=ethoxymethyl) or 3-oxabutyl(=2-methoxyethyl), 2-, 3-, or 4-oxapentyl, 2-, 3-, 4-, or 5-oxahexyl,2-, 3-, 4-, 5-, or 6-oxaheptyl, 2-, 3-, 4-, 5-, 6- or 7-oxaoctyl, 2-,3-, 4-, 5-, 6-, 7- or 8-oxanonyl or 2-, 3-, 4-, 5-, 6-, 7-, 8- or9-oxadecyl, for example.

In an alkyl group wherein one CH₂ group is replaced by —O— and one by—C(O)—, these radicals are preferably neighboured. Accordingly theseradicals together form a carbonyloxy group —C(O)—O— or an oxycarbonylgroup —O—C(O)—. Preferably this group is straight-chain and has 2 to 6 Catoms. It is accordingly preferably acetyloxy, propionyloxy, butyryloxy,pentanoyloxy, hexanoyloxy, acetyloxymethyl, propionyloxymethyl,butyryloxymethyl, pentanoyloxymethyl, 2-acetyloxyethyl,2-propionyloxyethyl, 2-butyryloxyethyl, 3-acetyloxypropyl,3-propionyloxypropyl, 4-acetyloxybutyl, methoxycarbonyl, ethoxycarbonyl,propoxycarbonyl, butoxycarbonyl, pentoxycarbonyl, methoxycarbonylmethyl,ethoxycarbonylmethyl, propoxycarbonylmethyl, butoxycarbonylmethyl,2-(methoxycarbonyl)ethyl, 2-(ethoxycarbonyl)ethyl,2-(propoxycarbonyl)ethyl, 3-(methoxycarbonyl)propyl,3-(ethoxycarbonyl)propyl, 4-(methoxycarbonyl)-butyl.

An alkyl group wherein two or more CH₂ groups are replaced by —O— and/or—C(O)O— can be straight-chain or branched. It is preferablystraight-chain and has 3 to 12 C atoms. Accordingly it is preferablybis-carboxy-methyl, 2,2-bis-carboxy-ethyl, 3,3-bis-carboxy-propyl,4,4-bis-carboxy-butyl, 5,5-bis-carboxy-pentyl, 6,6-bis-carboxy-hexyl,7,7-bis-carboxy-heptyl, 8,8-bis-carboxy-octyl, 9,9-bis-carboxy-nonyl,10,10-bis-carboxy-decyl, bis-(methoxycarbonyl)-methyl,2,2-bis-(methoxycarbonyl)-ethyl, 3,3-bis-(methoxycarbonyl)-propyl,4,4-bis-(methoxycarbonyl)-butyl, 5,5-bis-(methoxycarbonyl)-pentyl,6,6-bis-(methoxycarbonyl)-hexyl, 7,7-bis-(methoxycarbonyl)-heptyl,8,8-bis-(methoxycarbonyl)-octyl, bis-(ethoxycarbonyl)-methyl,2,2-bis-(ethoxycarbonyl)-ethyl, 3,3-bis-(ethoxycarbonyl)-propyl,4,4-bis-(ethoxycarbonyl)-butyl, 5,5-bis-(ethoxycarbonyl)-hexyl.

A thioalkyl group, i.e where one CH₂ group is replaced by —S—, ispreferably straight-chain thiomethyl (—SCH₃), 1-thioethyl (—SCH₂CH₃),1-thiopropyl (=—SCH₂CH₂CH₃), 1-(thiobutyl), 1-(thiopentyl),1-(thiohexyl), 1-(thioheptyl), 1-(thiooctyl), 1-(thiononyl),1-(thiodecyl), 1-(thioundecyl) or 1-(thiododecyl), wherein preferablythe CH₂ group adjacent to the sp² hybridised vinyl carbon atom isreplaced.

A fluoroalkyl group is preferably perfluoroalkyl C_(i)F_(2i+1), whereini is an integer from 1 to 15, in particular CF₃, C₂F₅, C₃F₇, C₄F₉,C₅F₁₁, C₆F₁₃, C₇F₁₅ or C₈F₁₇, very preferably C₆F₁₃, or partiallyfluorinated alkyl, in particular 1,1-difluoroalkyl, all of which arestraight-chain or branched.

The above-mentioned alkyl, alkoxy, alkenyl, oxaalkyl, thioalkyl,carbonyl and carbonyloxy groups can be achiral or chiral groups.Particularly preferred chiral groups are 2-butyl (=1-methylpropyl),2-methylbutyl, 2-methylpentyl, 3-methylpentyl, 2-ethylhexyl,2-propylpentyl, in particular 2-methylbutyl, 2-methylbutoxy,2-methylpentoxy, 3-methylpentoxy, 2-ethyl-hexoxy, 1-methylhexoxy,2-octyloxy, 2-oxa-3-methylbutyl, 3-oxa-4-methyl-pentyl, 4-methylhexyl,2-hexyl, 2-octyl, 2-nonyl, 2-decyl, 2-dodecyl, 6-meth-oxyoctoxy,6-methyloctoxy, 6-methyloctanoyloxy, 5-methylheptyloxy-carbonyl,2-methylbutyryloxy, 3-methylvaleroyloxy, 4-methylhexanoyloxy,2-chloropropionyloxy, 2-chloro-3-methylbutyryloxy,2-chloro-4-methyl-valeryl-oxy, 2-chloro-3-methylvaleryloxy,2-methyl-3-oxapentyl, 2-methyl-3-oxahexyl, 1-methoxypropyl-2-oxy,1-ethoxypropyl-2-oxy, 1-propoxypropyl-2-oxy, 1-butoxypropyl-2-oxy,2-fluorooctyloxy, 2-fluorodecyloxy, 1,1,1-trifluoro-2-octyloxy,1,1,1-trifluoro-2-octyl, 2-fluoromethyloctyloxy for example. Verypreferred are 2-hexyl, 2-octyl, 2-octyloxy, 1,1,1-trifluoro-2-hexyl,1,1,1-trifluoro-2-octyl and 1,1,1-trifluoro-2-octyloxy.

Preferred achiral branched groups are isopropyl, isobutyl(=methylpropyl), isopentyl (=3-methylbutyl), tert. butyl, isopropoxy,2-methyl-propoxy and 3-methylbutoxy.

In another preferred embodiment of the present invention, R¹⁻⁴ areindependently of each other selected from primary, secondary or tertiaryalkyl or alkoxy with 1 to 30 C atoms, wherein one or more H atoms areoptionally replaced by F, or aryl, aryloxy, heteroaryl or heteroaryloxythat is optionally alkylated or alkoxylated and has 4 to 30 ring atoms.Very preferred groups of this type are selected from the groupconsisting of the following formulae

wherein “ALK” denotes optionally fluorinated, preferably linear, alkylor alkoxy with 1 to 20, preferably 1 to 12 C-atoms, in case of tertiarygroups very preferably 1 to 9 C atoms, and the dashed line denotes thelink to the ring to which these groups are attached. Especiallypreferred among these groups are those wherein all ALK subgroups areidentical.

—CY¹═CY²— is preferably —CH═CH—, —CF═CF— or —CH═C(CN)—.

Halogen is F, Cl, Br or I, preferably F, Cl or Br.

—CO—, —C(═O)— and —C(O)— denote a carbonyl group, i.e.

The polymers according to the present invention may also be substitutedwith a polymerisable or crosslinkable reactive group, which isoptionally protected during the process of forming the polymer.Particular preferred units polymers of this type are those comprisingone or more units of formula I wherein one or more of R¹⁻⁴ denote orcontain a group P-Sp-. These units and polymers are particularly usefulas semiconductors or charge transport materials, as they can becrosslinked via the groups P, for example by polymerisation in situ,during or after processing the polymer into a thin film for asemiconductor component, to yield crosslinked polymer films with highcharge carrier mobility and high thermal, mechanical and chemicalstability.

Preferably the polymerisable or crosslinkable group P is selected fromCH₂═CW¹—C(O)—O—, CH₂═CW¹—C(O)—,

CH₂═CW²—(O)_(k1)—, CW¹═CH—C(O)—(O)_(k3)—, CW¹═CH—C(O)—NH—,CH₂═CW¹—C(O)—NH—, CH₃—CH═CH—O—, (CH₂═CH)₂CH—OC(O)—,(CH₂═CH—CH₂)₂CH—O—C(O)—, (CH₂═CH)₂CH—O—, (CH₂═CH—CH₂)₂N—,(CH₂═CH—CH₂)₂N—C(O)—, HO—CW²W³—, HS—CW²W³—, HW²N—, HO—CW²W³—NH—,CH₂═CH—(C(O)—O)_(k1)-Phe-(O)_(k2)—, CH₂═CH—(C(O))_(k1)-Phe-(O)_(k2)—,Phe-CH═CH—, HOOC—, OCN—, and W⁴W⁵W⁶Si—, with W¹ being H, F, Cl, CN, CF₃,phenyl or alkyl with 1 to 5 C-atoms, in particular H, Cl or CH₃, W² andW³ being independently of each other H or alkyl with 1 to 5 C-atoms, inparticular H, methyl, ethyl or n-propyl, W⁴, W⁵ and W⁶ beingindependently of each other Cl, oxaalkyl or oxacarbonylalkyl with 1 to 5C-atoms, W⁷ and W⁸ being independently of each other H, Cl or alkyl with1 to 5 C-atoms, Phe being 1,4-phenylene that is optionally substitutedby one or more groups L as defined above, k₁, k₂ and k₃ beingindependently of each other 0 or 1, k₃ preferably being 1, and k₄ beingan integer from 1 to 10.

Alternatively P is a protected derivative of these groups which isnon-reactive under the conditions described for the process according tothe present invention. Suitable protective groups are known to theordinary expert and described in the literature, for example in Green,“Protective Groups in Organic Synthesis”, John Wiley and Sons, New York(1981), like for example acetals or ketals.

Especially preferred groups P are CH₂═CH—C(O)—O—, CH₂═C(CH₃)—C(O)—O—,CH₂═CF—C(O)—O—, CH₂═CH—O—, (CH₂═CH)₂CH—O—C(O)—, (CH₂═CH)₂CH—O—,

or protected derivatives thereof. Further preferred groups P areselected from the group consisting of vinyloxy, acrylate, methacrylate,fluoroacrylate, chloroacrylate, oxetan and epoxy groups, very preferablyfrom an acrylate or methacrylate group.

Polymerisation of group P can be carried out according to methods thatare known to the ordinary expert and described in the literature, forexample in D. J. Broer; G. Challa; G. N. Mol, Macromol. Chem, 1991, 192,59.

The term “spacer group” is known in prior art and suitable spacer groupsSp are known to the ordinary expert (see e.g. Pure Appl. Chem. 73(5),888 (2001). The spacer group Sp is preferably of formula Sp′-X′, suchthat P-Sp- is P-Sp′-X′—, wherein

-   Sp′ is alkylene with up to 30 C atoms which is unsubstituted or    mono- or polysubstituted by F, Cl, Br, I or CN, it being also    possible for one or more non-adjacent CH₂ groups to be replaced, in    each case independently from one another, by —O—, —S—, —NH—, —NR⁰—,    —SiR⁰R⁰⁰—, —C(O)—, —C(O)O—, —OC(O)—, —OC(O)—O—, —S—C(O)—, —C(O)—S—,    —CH═CH— or —C≡C— in such a manner that O and/or S atoms are not    linked directly to one another,-   X′ is —O—, —S—, —C(O)—, —C(O)O—, —OC(O)—, —O—C(O)O—, —C(O)—NR⁰—,    —NR⁰—C(O)—, —NR⁰—C(O)—NR⁰⁰—, —OCH₂—, —CH₂O—, —SCH₂—, —CH₂S—, —CF₂O—,    —OCF₂—, —CF₂S—, —SCF₂—, —CF₂CH₂—, —CH₂CF₂—, —CF₂CF₂—, —CH═N—,    —N═CH—, —N═N—, —CH═CR⁰—, —CY¹═CY²—, —C≡C—, —CH═CH—C(O)O—,    —OC(O)—CH═CH— or a single bond,-   R⁰ and R⁰⁰ are independently of each other H or alkyl with 1 to 12    C-atoms, and-   Y¹ and Y² are independently of each other H, F, Cl or CN.

X′ is preferably —O—, —S—, —OCH₂—, —CH₂O—, —SCH₂—, —CH₂S—, —CF₂O—,—OCF₂—, —CF₂S—, —SCF₂—, —CH₂CH₂—, —CF₂CH₂—, —CH₂CF₂—, —CF₂CF₂—, —CH═N—,—N═CH—, —N═N—, —CH═CR⁰—, —CY¹═CY²—, —C≡C— or a single bond, inparticular —O—, —S—, —C≡C—, —CY¹═CY²— or a single bond. In anotherpreferred embodiment X′ is a group that is able to form a conjugatedsystem, such as —C≡C— or —CY¹═CY²—, or a single bond.

Typical groups Sp′ are, for example, —(CH₂)_(p)—,—(CH₂CH₂O)_(q)—CH₂CH₂—, —CH₂CH₂—S—CH₂CH₂— or —CH₂CH₂—NH—CH₂CH₂— or—(SiR⁰R⁰⁰—O)_(p)—, with p being an integer from 2 to 12, q being aninteger from 1 to 3 and R⁰ and R⁰⁰ having the meanings given above.

Preferred groups Sp′ are ethylene, propylene, butylene, pentylene,hexylene, heptylene, octylene, nonylene, decylene, undecylene,dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene,ethylene-thioethylene, ethylene-N-methyl-iminoethylene,1-methylalkylene, ethenylene, propenylene and butenylene for example.

Preferably in the units of formula I X¹ and X² denote S or C(R³R⁴) orC═O, very preferably S.

Preferably in the units of formula I T¹ is S and T² is CH.

Preferably the units of formula I are selected from the followingformulae:

wherein R¹⁻⁴ have the meanings of formula I as given above and below.

In the units of formula I and its preferred subformulae, R¹ and R²preferably denote straight-chain, branched or cyclic alkyl with 1 to 30C atoms which is unsubstituted or substituted by one or more F atoms.

Further preferably one of R¹ and R² is H and the other is different fromH, and is preferably straight-chain, branched or cyclic alkyl with 1 to30 C atoms which is unsubstituted or substituted by one or more F atoms.

Further preferably R¹ and/or R² are independently of each other selectedfrom the group consisting of aryl and heteroaryl, each of which isoptionally fluorinated, alkylated or alkoxylated and has 4 to 30 ringatoms.

If R¹ and/or R² in formula I denote substituted aryl or heteroaryl, itis preferably substituted by one or more groups L, wherein L is selectedfrom P-Sp-, F, Cl, Br, I, —OH, —CN, —NO₂, —NCO, —NCS, —OCN, —SCN,—C(═O)NR⁰R⁰⁰, —C(═O)X⁰, —C(═O)R⁰, —NR⁰R⁰⁰, C(═O)OH, optionallysubstituted aryl or heteroaryl having 4 to 20 ring atoms, or straightchain, branched or cyclic alkyl with 1 to 20, preferably 1 to 12 C atomswherein one or more non-adjacent CH₂ groups are optionally replaced, ineach case independently from one another, by —O—, —S—, —NR⁰—, —SiR⁰R⁰⁰—,—C(═O)—, —C(═O)O—, —CY¹═CY²— or —C≡C— in such a manner that O and/or Satoms are not linked directly to one another and which is unsubstitutedor substituted with one or more F or Cl atoms or OH groups, X⁰ ishalogen, preferably F, Cl or Br, and Y¹, Y², R⁰ and R⁰⁰ have themeanings given above and below.

Preferably R¹ and/or R² in formula I denote aryl or heteroaryl that issubstituted by one or more straight-chain, branched or cyclic alkylgroups with 1 to 30 C atoms, in which one or more non-adjacent CH₂groups are optionally replaced by one or more non-adjacent CH₂ groupsare optionally replaced by —O—, —S—, —C(O)—, —C(O)—O—, —O—C(O)—,—O—C(O)—O—, —NR⁰—, —SiR⁰R⁰⁰—, —CF₂—, —CHR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C— insuch a manner that O and/or S atoms are not linked directly to oneanother, and in which one or more H atoms are optionally replaced by F,Cl, Br, I or CN.

In the units of formula I and its preferred subformulae, R³ and R⁴ havepreferably one of the preferred meanings of R¹ and R² as given above.

Preferred polymers according to the present invention comprise one ormore repeating units of formula II:—[(Ar¹)_(a)—(U)_(b)—(Ar²)_(c)—(Ar³)_(d)]—  IIwherein

-   U is a unit of formula I,-   Ar¹, Ar², Ar³ are, on each occurrence identically or differently,    and independently of each other, aryl or heteroaryl that is    different from U, preferably has 5 to 30 ring atoms, and is    optionally substituted, preferably by one or more groups R^(S),-   R^(S) is on each occurrence identically or differently F, Br, Cl,    —CN, —NC, —NCO, —NCS, —OCN, —SCN, —C(O)NR⁰R⁰⁰, —C(O)X⁰, —C(O)R⁰,    —C(O)OR⁰, —NH₂, —NR⁰R⁰⁰, —SH, —SR⁰, —SO₃H, —SO₂R⁰, —OH, —NO₂, —CF₃,    —SF₅, optionally substituted silyl, carbyl or hydrocarbyl with 1 to    40 C atoms that is optionally substituted and optionally comprises    one or more hetero atoms, or P-Sp-,-   R⁰ and R⁰⁰ are independently of each other H or optionally    substituted C₁₋₄₀ carbyl or hydrocarbyl, and preferably denote H or    alkyl with 1 to 12 C-atoms,-   P is a polymerisable or crosslinkable group,-   Sp is a spacer group or a single bond,-   X⁰ is halogen, preferably F, Cl or Br,-   a, b and c are on each occurrence identically or differently 0, 1 or    2,-   d is on each occurrence identically or differently 0 or an integer    from 1 to 10,    wherein the polymer comprises at least one repeating unit of formula    II wherein b is at least 1.

Further preferred polymers according to the present invention comprise,in addition to the units of formula I or II, one or more repeating unitsselected from monocyclic or polycyclic aryl or heteroaryl groups thatare optionally substituted.

These additional repeating units are preferably selected of formula III—[(Ar¹)_(a)-(A^(c))_(b)-(Ar²)_(c)—(Ar³)_(d)]—  IIIwherein Ar¹, Ar², Ar³, a, b, c and d are as defined in formula II, andA^(c) is an aryl or heteroaryl group that is different from U and Ar¹⁻³,preferably has 5 to 30 ring atoms, is optionally substituted by one ormore groups R^(S) as defined above and below, and is preferably selectedfrom aryl or heteroaryl groups having electron acceptor properties,wherein the polymer comprises at least one repeating unit of formula IIIwherein b is at least 1.

R^(S) preferably has one of the meanings given for R¹.

The conjugated polymers according to the present invention arepreferably selected of formula IV:*

(A)_(x)-(B)_(y)

_(n)*  IVwherein

-   A is a unit of formula I or II or its preferred subformulae,-   B is a unit that is different from A and comprises one or more aryl    or heteroaryl groups that are optionally substituted, and is    preferably selected of formula III,-   x is >0 and ≦1,-   y is ≧0 and <1,-   x+y is 1, and-   n is an integer>1.

Preferred polymers of formula IV are selected of the following formulae*—[(Ar¹—U—Ar²)_(x)—(Ar³)_(y)]_(n)—*  IVa*—[(Ar¹—U—Ar²)_(x)—(Ar³—Ar³)_(y)]_(n)—*  IVb*—[(Ar¹—U—Ar²)_(x)—(Ar³—Ar³—Ar³)_(y)]_(n)—*  IVc*—[(Ar¹)_(a)—(U)_(b)—(Ar²)_(c)—(Ar³)_(d)]_(n)—*  IVd*—([(Ar¹)_(a)—(U)_(b)—(Ar²)_(c)—(Ar³)_(d)]_(x)—[(Ar¹)_(a)-(A^(c))_(b)-(Ar²)_(c)—(Ar³)_(d)]_(y))_(n)—*  IVewherein U, Ar¹, Ar², Ar³, a, b, c and d have in each occurrenceidentically or differently one of the meanings given in formula II,A^(c) has on each occurrence identically or differently one of themeanings given in formula III, and x, y and n are as defined in formulaIV, wherein these polymers can be alternating or random copolymers, andwherein in formula IVd and IVe in at least one of the repeating units[(Ar¹)_(a)—(U)_(b)—(Ar²)_(c)—(Ar³)_(d)] and in at least one of therepeating units [(Ar¹)_(a)-(A^(c))_(b)-(Ar²)_(c)—(Ar³)_(d)] b is atleast 1.

In the polymers according to the present invention, the total number ofrepeating units n is preferably from 2 to 10,000. The total number ofrepeating units n is preferably ≧5, very preferably ≧10, most preferably≧50, and preferably ≦500, very preferably ≦1,000, most preferably≦2,000, including any combination of the aforementioned lower and upperlimits of n.

The polymers of the present invention include homopolymers andcopolymers, like statistical or random copolymers, alternatingcopolymers and block copolymers, as well as combinations thereof.

Especially preferred are polymers selected from the following groups:

-   -   Group A consisting of homopolymers of the unit U or (Ar¹—U) or        (Ar¹—U—Ar²) or (Ar¹—U—Ar³) or (U—Ar²—Ar³) or (Ar¹—U—Ar²—Ar³),        i.e. where all repeating units are identical,    -   Group B consisting of random or alternating copolymers formed by        identical units (Ar¹—U—Ar²) and identical units (Ar³),    -   Group C consisting of random or alternating copolymers formed by        identical units (Ar¹—U—Ar²) and identical units (A¹),    -   Group D consisting of random or alternating copolymers formed by        identical units (Ar¹—U—Ar²) and identical units (Ar¹-A^(c)-Ar²),        wherein in all these groups U, A^(c), Ar¹, Ar² and Ar³ are as        defined above and below, in groups A, B and C Ar¹, Ar² and Ar³        are different from a single bond, and in group D one of Ar¹ and        Ar² may also denote a single bond.

Preferred polymers of formula IV and IVa to IVe are selected of formulaVR⁵-chain-R⁶  Vwherein “chain” denotes a polymer chain of formulae IV or IVa to IVe,and R⁵ and R⁶ have independently of each other one of the meanings of R¹as defined above, or denote, independently of each other, H, F, Br, Cl,I, —CH₂Cl, —CHO, —CR′═CR″₂, —SiR′R″R′″, —SiR′X′X″, —SiR′R″X′,—SnR′R″R′″, —BR′R″, —B(OR′)(OR″), —B(OH)₂, —O—SO₂—R′, —C≡CH, —C≡C—SiR′₃,—ZnX′, P-Sp- or an endcap group, wherein P and Sp are as defined informula II, X′ and X″ denote halogen, R′, R″ and R′″ have independentlyof each other one of the meanings of R⁰ given in formula I, and two ofR′, R″ and R′″ may also form a ring together with the hetero atom towhich they are attached.

Preferred endcap groups R⁵ and R⁶ are H, C₁₋₂₀ alkyl, or optionallysubstituted C₆₋₁₂ aryl or C₂₋₁₀ heteroaryl, very preferably H or phenyl.

In the polymers represented by formula IV, IVa to IVe and V, x denotesthe mole fraction of units A, y denotes the mole fraction of units B,and n denotes the degree of polymerisation or total number of units Aand B. These formulae includes block copolymers, random or statisticalcopolymers and alternating copolymers of A and B, as well ashomopolymers of A for the case when x is >0 and y is 0.

Another aspect of the invention relates to monomers of formula VIR⁷—(Ar¹)_(a)—U—(Ar²)_(b)—R⁸  VIwherein U, Ar¹, Ar², a and b have the meanings of formula II, or one ofthe preferred meanings as described above and below, and R⁷ and R⁸ are,preferably independently of each other, selected from the groupconsisting of Cl, Br, I, O-tosylate, O-triflate, O-mesylate,O-nonaflate, —SiMe₂F, —SiMeF₂, —O—SO₂Z¹, —B(OZ²)₂, —CZ³═C(Z³)₂, —C≡CH,—C≡CSi(Z¹)₃, —ZnX⁰ and —Sn(Z⁴)₃, wherein X⁰ is halogen, preferably Cl,Br or I, Z¹⁻⁴ are selected from the group consisting of alkyl and aryl,each being optionally substituted, and two groups Z² may also togetherform a cyclic group.

Especially preferred are monomers of the following formulaeR⁷—Ar¹—U—Ar²—R⁸  VI1R⁷—U—R⁸  VI2R⁷—Ar¹—U—R⁸  VI3R⁷—U—Ar²—R⁸  VI4wherein U, Ar¹, Ar², R⁷ and R⁸ are as defined in formula VI.

Especially preferred are repeating units, monomers and polymers offormulae I, II, III, IV, IVa-IVe, V, VI and their subformulae whereinone or more of Ar¹, Ar² and Ar³ denote aryl or heteroaryl, preferablyhaving electron donor properties, selected from the group consisting ofthe following formulae

wherein one of X¹¹ and X¹² is S and the other is Se, and R¹¹, R¹², R¹³,R¹⁴, R¹⁵, R¹⁶, R¹⁷ and R¹⁸ independently of each other denote H or haveone of the meanings of R¹ as defined above and below.

Preferably one or more of Ar¹, Ar² and Ar³ are selected from the groupconsisting of formulae D1, D2, D3, D4, D5, D6, D7, D15, D17, D19, D24,D25, D29 and D26, very preferably from formulae D1, D2, D3, D5, D15, D24and D29.

In another preferred embodiment invention in formula D1 R¹¹ and R¹²denote H or F. In another preferred embodiment of the present inventionin formulae D2, D5, D6, D15, D16 and D24 R¹¹ and R¹² denote H or F.

Further preferred are repeating units, monomers and polymers of formulaeI, II, III, IV, IVa to IVe, V, VI and their subformulae wherein A^(c)and/or Ar³ denotes aryl or heteroaryl, preferably having electronacceptor properties, selected from the group consisting of the followingformulae

wherein one of X¹¹ and X¹² is S and the other is Se, and R¹¹, R¹², R¹³,R¹⁴ and R¹⁵ independently of each other denote H or have one of themeanings of R¹ as defined above and below.

Preferably A and/or Ar³ is selected from the group consisting offormulae A1, A2, A3, A4, A5, A10, A34, A44, very preferably from formulaA2 and A3.

Especially preferred copolymers of the following formulae:—(U)_(x)—  IVa—(U)_(x)—(Ar)_(x)—  IVb—(U—Ar)_(n)—  IVcwherein U and Ar¹ are as defined in formula II, and n, x and y are asdefined in formula IV.

Further preferred are copolymers of formula IVa, IVb and IVc wherein Uis selected from the group consisting of preferred subformulae Ia-Ihabove, and Ar¹ is selected from the group consisting of the followingunits:

wherein R¹⁻⁴ are as defined in formula I.

Further preferred are copolymers selected from the following subformulae

wherein R¹ and R² are as defined in formula I and n is as defined informula IV.

Further preferred are repeating units, monomers and polymers of formulaeI-VI and their subformulae selected from the following list of preferredembodiments:

-   -   y is ≧0 and ≦1,    -   b=d=1 and a=c=0, preferably in all repeating units,    -   a=b=c=d=1, preferably in all repeating units,    -   a=b=d=1 and c=0, preferably in all repeating units,    -   a=b=c=1 and d=0, preferably in all repeating units,    -   a=c=2, b=1 and d=0, preferably in all repeating units,    -   a=c=2 and b=d=1, preferably in all repeating units,    -   X¹ and X² are S,    -   X¹ and X² are C(R³R⁴),    -   X¹ and X² are Si(R³R⁴),    -   X¹ and X² are C═O,    -   W¹ and W² are C(R¹R²),    -   W¹ and W² are C═C(R¹R²),    -   W¹ and W² are Si(R¹R²),    -   W¹ and W² are C═O,    -   T¹ is S and T² is CH,    -   n is at least 5, preferably at least 10, very preferably at        least 50, and up to 2,000, preferably up to 500.    -   M_(w) is at least 5,000, preferably at least 8,000, very        preferably at least 10,000, and preferably up to 300,000, very        preferably up to 100,000,    -   one of R¹ and R² is H and the other is different from H,    -   R¹ and R² are different from H,    -   R¹ and/or R² are independently of each other selected from the        group consisting of primary alkyl with 1 to 30 C atoms,        secondary alkyl with 3 to 30 C atoms, and tertiary alkyl with 4        to 30 C atoms, wherein in all these groups one or more H atoms        are optionally replaced by F,    -   R¹ and/or R² are independently of each other selected from the        group consisting of aryl and heteroaryl, each of which is        optionally fluorinated, alkylated or alkoxylated and has 4 to 30        ring atoms,    -   R¹ and/or R² are independently of each other selected from the        group consisting of primary alkoxy or sulfanylalkyl with 1 to 30        C atoms, secondary alkoxy or sulfanylalkyl with 3 to 30 C atoms,        and tertiary alkoxy or sulfanylalkyl with 4 to 30 C atoms,        wherein in all these groups one or more H atoms are optionally        replaced by F,    -   R¹ and/or R² are independently of each other selected from the        group consisting of aryloxy and heteroaryloxy, each of which is        optionally alkylated or alkoxylated and has 4 to 30 ring atoms,    -   R¹ and/or R² are independently of each other selected from the        group consisting of alkylcarbonyl, alkoxycarbonyl and        alkylcarbonyloxy, all of which are straight-chain or branched,        are optionally fluorinated, and have from 1 to 30 C atoms,    -   one of R³ and R⁴ is H and the other is different from H,    -   R³ and R⁴ are different from H,    -   R³ and/or R⁴ are independently of each other selected from the        group consisting of primary alkyl with 1 to 30 C atoms,        secondary alkyl with 3 to 30 C atoms, and tertiary alkyl with 4        to 30 C atoms, wherein in all these groups one or more H atoms        are optionally replaced by F,    -   R³ and/or R⁴ are independently of each other selected from the        group consisting of aryl and heteroaryl, each of which is        optionally fluorinated, alkylated or alkoxylated and has 4 to 30        ring atoms,    -   R³ and/or R⁴ are independently of each other selected from the        group consisting of primary alkoxy or sulfanylalkyl with 1 to 30        C atoms, secondary alkoxy or sulfanylalkyl with 3 to 30 C atoms,        and tertiary alkoxy or sulfanylalkyl with 4 to 30 C atoms,        wherein in all these groups one or more H atoms are optionally        replaced by F,    -   R³ and/or R⁴ are independently of each other selected from the        group consisting of aryloxy and heteroaryloxy, each of which is        optionally alkylated or alkoxylated and has 4 to 30 ring atoms,    -   R³ and/or R⁴ are independently of each other selected from the        group consisting of alkylcarbonyl, alkoxycarbonyl and        alkylcarbonyloxy, all of which are straight-chain or branched,        are optionally fluorinated, and have from 1 to 30 C atoms,    -   R⁰ and R⁰⁰ are selected from H or C₁-C₁₀-alkyl,    -   R⁵ and R⁶ are selected from H, halogen, —CH₂Cl, —CHO,        —CH═CH₂—SiR′R″R′″, —SnR′R″R′″, —BR′R″, —B(OR′)(OR″), —B(OH)₂,        P-Sp, C₁-C₂₀-alkyl, C₁-C₂₀-alkoxy, C₂-C₂₀-alkenyl,        C₁-C₂₀-fluoroalkyl and optionally substituted aryl or        heteroaryl, preferably phenyl,    -   R⁷ and R⁸ are, preferably independently of each other, selected        from the group consisting of Cl, Br, I, O-tosylate, O-triflate,        O-mesylate, O-nonaflate, —SiMe₂F, —SiMeF₂, —O—SO₂Z¹, —B(OZ²)₂,        —CZ³═C(Z⁴)₂, —C≡CH, C≡CSi(Z¹)₃, —ZnX⁰ and —Sn(Z⁴)₃, wherein X⁰        is halogen, Z¹⁻⁴ are selected from the group consisting of alkyl        and aryl, each being optionally substituted, and two groups Z²        may also form a cyclic group.

The compounds of the present invention can be synthesized according toor in analogy to methods that are known to the skilled person and aredescribed in the literature. Other methods of preparation can be takenfrom the examples. For example, the polymers can be suitably prepared byaryl-aryl coupling reactions, such as Yamamoto coupling, Suzukicoupling, Stille coupling, Sonogashira coupling, Heck coupling orBuchwald coupling. Suzuki coupling and Yamamoto coupling are especiallypreferred. The monomers which are polymerised to form the repeat unitsof the polymers can be prepared according to methods which are known tothe person skilled in the art.

Preferably the polymers are prepared from monomers of formula VI ortheir preferred subformulae as described above and below.

Another aspect of the invention is a process for preparing a polymer bycoupling one or more identical or different monomeric units of formula Ior monomers of formula VI with each other and/or with one or morecomonomers in a polymerisation reaction, preferably in an aryl-arylcoupling reaction.

Suitable and preferred comonomers are selected from the followingformulaeR⁷—(Ar¹)_(a)-A^(c)-(Ar²)_(c)—R⁸  CR⁷—Ar¹—R⁸  DR⁷—Ar³—R⁸  Ewherein Ar¹, Ar², Ar³, a and c have one of the meanings of formula II orone of the preferred meanings given above and below, A^(c) has one ofthe meanings of formula III or one of the preferred meanings given aboveand below, and R⁷ and R⁸ have one of meanings of formula VI or one ofthe preferred meanings given above and below.

Very preferred is a process for preparing a polymer by coupling one ormore monomers selected from formula VI or formulae VI1-VI4 with one ormore monomers of formula C, and optionally with one or more monomersselected from formula D and E, in an aryl-aryl coupling reaction,wherein preferably R⁷ and R⁸ are selected from Cl, Br, I, —B(OZ²)₂ and—Sn(Z⁴)₃.

For example, preferred embodiments of the present invention relate to

a) a process of preparing a polymer by coupling a monomer of formula VI1R⁷—Ar¹—U—Ar²—R⁸  VI1with a monomer of formula D1R⁷—Ar¹—R⁸  D1in an aryl-aryl coupling reaction,orb) a process of preparing a polymer by coupling a monomer of formula VI2R⁷—U—R⁸  VI2with a monomer of formula C1R⁷—Ar¹-A^(c)-Ar²—R⁸  C1in an aryl-aryl coupling reaction,orc) a process of preparing a polymer by coupling a monomer of formula VI2R⁷—U—R⁸  VI2with a monomer of formula C₂R⁷-A^(c)-R⁸  C2in an aryl-aryl coupling reaction, ord) a process of preparing a polymer by coupling a monomer of formula VI2R⁷—U—R⁸  VI2with a monomer of formula C2R⁷-A^(c)-R⁸  C1and a monomer of formula D1R⁷—Ar¹—R⁸  D1in an aryl-aryl coupling reaction,wherein R⁷, R⁸, U, A^(c), Ar^(1,2) are as defined in formula II, III andVI, and R⁷ and R⁸ are preferably selected from Cl, Br, I, —B(OZ²)₂ and—Sn(Z⁴)₃ as defined in formula VI.

Preferred aryl-aryl coupling methods used in the processes describedabove and below are Yamamoto coupling, Kumada coupling, Negishicoupling, Suzuki coupling, Stille coupling, Sonogashira coupling, Heckcoupling, C—H activation coupling, Ullmann coupling or Buchwaldcoupling. Especially preferred are Suzuki coupling, Negishi coupling,Stille coupling and Yamamoto coupling. Suzuki coupling is described forexample in WO 00/53656 A1. Negishi coupling is described for example inJ. Chem. Soc., Chem. Commun., 1977, 683-684. Yamamoto coupling isdescribed in for example in T. Yamamoto et al., Prog. Polym. Sci., 1993,17, 1153-1205, or WO 2004/022626 A1. For example, when using Yamamotocoupling, monomers having two reactive halide groups are preferablyused. When using Suzuki coupling, monomers having two reactive boronicacid or boronic acid ester groups or two reactive halide groups arepreferably used. When using Stille coupling, monomers having tworeactive stannane groups or two reactive halide groups are preferablyused. When using Negishi coupling, monomers having two reactiveorganozinc groups or two reactive halide groups are preferably used.

Suzuki and Stille polymerisation may be used to prepare homopolymers aswell as statistical, alternating and block random copolymers.Statistical or block copolymers can be prepared for example from theabove monomers wherein one of the reactive groups is halogen and theother reactive group is a boronic acid, boronic acid derivative group orand alkylstannane. The synthesis of statistical, alternating and blockcopolymers is described in detail for example in WO 03/048225 A2 or WO2005/014688 A2.

Preferred catalysts, especially for Suzuki, Negishi or Stille coupling,are selected from Pd(0) complexes or Pd(II) salts. Preferred Pd(0)complexes are those bearing at least one phosphine ligand such asPd(Ph₃P)₄. Another preferred phosphine ligand istris(ortho-tolyl)phosphine, i.e. Pd(o-Tol₃P)₄.

Preferred Pd(II) salts include palladium acetate, i.e. Pd(OAc)₂.Alternatively the Pd(0) complex can be prepared by mixing a Pd(0)dibenzylideneacetone complex, for exampletris(dibenzyl-ideneacetone)dipalladium(0),bis(dibenzylideneacetone)palladium(0), or Pd(II) salts e.g. palladiumacetate, with a phosphine ligand, for example triphenylphosphine,tris(ortho-tolyl)phosphine or tri(tert-butyl)phosphine. Suzuki couplingis performed in the presence of a base, for example sodium carbonate,potassium carbonate, lithium hydroxide, potassium phosphate or anorganic base such as tetraethylammonium carbonate or tetraethylammoniumhydroxide. Yamamoto coupling employs a Ni(0) complex, for examplebis(1,5-cyclooctadienyl) nickel(0).

As alternatives to halogens as described above, leaving groups offormula —O—SO₂Z¹ can be used wherein Z¹ is as described above.Particular examples of such leaving groups are tosylate, mesylate andtriflate.

Especially suitable and preferred synthesis methods of the repeatingunits, monomers and polymers of formulae I-VI and their subformulae areillustrated in the synthesis schemes shown hereinafter, wherein R¹⁻⁴have the meanings given above.

For the DTT derivatives of formula I, the most preferred synthetic routeis to go through a the intermediate 3 which is synthesised via thecross-coupling of 2-functionalised dithieno[3,2-b;2′,3′-d]thiophene(DTT) with diethyl 2,5-dibromoterephthalate (2), as shown in Scheme 1.Terephthalate 3 is then treated with alkylphenyllithium oralkylphenylmagnesium halide to yield the diol 5, which is subsequentlydouble ring-closed upon treating with an acid, to yield directly thetetra substituted derivative 6.

The CDT derivatives of formula I can be synthesized analogously asdescribed in Scheme 1. In addition, the solubilising groups on the CDTbuilding block 7 permits a second synthetic route for this class ofcompounds (Scheme 2). The diester 8 prepared from a cross-coupling ofCDT 7 with 2, is hydrolysed to terephthalic acid (9), which is convertedto the corresponding terephthaloyl dichloride by reacting with oxalylchloride or thionyl chloride. Terephthaloyl dichloride is thendouble-ring-closed to the quinoid form 10, which is then reduced to theunsubstituted core structure 11.

IDCDT 11 can be tetra-alkylated with alkyl halides under basicconditions to afford 13. It can also be solubilised using alkylidenegroups by reacting 11 with an aldehyde or a ketone to yield 12.Alternatively, terephthalate 8 is treated with alkylphenyllithium oralkylphenylmagnesium halide to yield the diol 14, which is subsequentlydouble ring-closed upon treating with an acid, to yield directly thetetra substituted derivative 15.

In the third approach (Scheme 3), diester 18 prepared from across-coupling of IDT 16 with 17, is hydrolysed to diacid (19), which isconverted to the corresponding acid chloride by reacting with oxalylchloride or thionyl chloride. Diacid chloride is then double-ring-closedto the quinoid form 20, which is then reduced to the unsubstituted corestructure 21. IDCDT 21 can be tetra-alkylated with alkyl halides underbasic conditions to afford 23. It can also be solubilised usingalkylidene groups by reacting 21 with an aldehyde or a ketone to yield22.

The preferred functionalisation reactions of the solubilised IDDTT andIDCDT are shown in Scheme 4. These reactions are generally, but notlimited to, e.g., bromination with N-bromosuccinamide or elementalbromine, or lithiation with organolithium reagents then reacting withalkyl boronic esters to yield the diboronic acids and esters, or withtrialkylstannyl chlorides to yield the distannanes.

Polymerisation reactions are shown in Scheme 5.

The novel methods of preparing monomers and polymers as described aboveand below are another aspect of the invention.

The compounds and polymers according to the present invention can alsobe used in mixtures or polymer blends, for example together withmonomeric compounds or together with other polymers havingcharge-transport, semiconducting, electrically conducting,photoconducting and/or light emitting semiconducting properties, or forexample with polymers having hole blocking or electron blockingproperties for use as interlayers or charge blocking layers in OLEDdevices. Thus, another aspect of the invention relates to a polymerblend comprising one or more polymers according to the present inventionand one or more further polymers having one or more of theabove-mentioned properties. These blends can be prepared by conventionalmethods that are described in prior art and known to the skilled person.Typically the polymers are mixed with each other or dissolved insuitable solvents and the solutions combined.

Another aspect of the invention relates to a formulation comprising oneor more small molecules, polymers, mixtures or polymer blends asdescribed above and below and one or more organic solvents.

Preferred solvents are aliphatic hydrocarbons, chlorinated hydrocarbons,aromatic hydrocarbons, ketones, ethers and mixtures thereof. Additionalsolvents which can be used include 1,2,4-trimethylbenzene,1,2,3,4-tetra-methyl benzene, pentylbenzene, mesitylene, cumene, cymene,cyclohexylbenzene, diethylbenzene, tetralin, decalin, 2,6-lutidine,2-fluoro-m-xylene, 3-fluoro-o-xylene, 2-chlorobenzotrifluoride,N,N-dimethylformamide, 2-chloro-6-fluorotoluene, 2-fluoroanisole,anisole, 2,3-dimethylpyrazine, 4-fluoroanisole, 3-fluoroanisole,3-trifluoro-methylanisole, 2-methylanisole, phenetol, 4-methylanisole,3-methylanisole, 4-fluoro-3-methylanisole, 2-fluorobenzonitrile,4-fluoroveratrol, 2,6-dimethylanisole, 3-fluorobenzo-nitrile,2,5-dimethylanisole, 2,4-dimethylanisole, benzonitrile,3,5-dimethyl-anisole, N,N-dimethylaniline, ethyl benzoate,1-fluoro-3,5-dimethoxy-benzene, 1-methylnaphthalene,N-methylpyrrolidinone, 3-fluorobenzo-trifluoride, benzotrifluoride,dioxane, trifluoromethoxy-benzene, 4-fluorobenzotrifluoride,3-fluoropyridine, toluene, 2-fluoro-toluene, 2-fluorobenzotrifluoride,3-fluorotoluene, 4-isopropylbiphenyl, phenyl ether, pyridine,4-fluorotoluene, 2,5-difluorotoluene, 1-chloro-2,4-difluorobenzene,2-fluoropyridine, 3-chlorofluorobenzene, 1-chloro-2,5-difluorobenzene,4-chlorofluorobenzene, chloro-benzene, o-dichlorobenzene,2-chlorofluorobenzene, p-xylene, m-xylene, o-xylene or mixture of o-,m-, and p-isomers. Solvents with relatively low polarity are generallypreferred. For inkjet printing solvents and solvent mixtures with highboiling temperatures are preferred. For spin coating alkylated benzeneslike xylene and toluene are preferred.

Examples of especially preferred solvents include, without limitation,dichloromethane, trichloromethane, chlorobenzene, o-dichlorobenzene,tetrahydrofuran, anisole, morpholine, toluene, o-xylene, m-xylene,p-xylene, 1,4-dioxane, acetone, methylethylketone, 1,2-dichloroethane,1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, ethyl acetate, n-butylacetate, N,N-dimethylformamide, dimethylacetamide, dimethylsulfoxide,tetraline, decaline, indane, methyl benzoate, ethyl benzoate, mesityleneand/or mixtures thereof.

Additional solvents include solvents or co-solvents of the followingformula

where Z¹¹ is O, S or CH═CH, X¹¹ is halogen, Y¹¹ is methyl, x1 is 0 or 1,and y1 is 1 or 2.

The concentration of the compounds or polymers in the solution ispreferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight.Optionally, the solution also comprises one or more binders to adjustthe rheological properties, as described for example in WO 2005/055248A1.

After the appropriate mixing and ageing, solutions are evaluated as oneof the following categories: complete solution, borderline solution orinsoluble.

The contour line is drawn to outline the solubility parameter-hydrogenbonding limits dividing solubility and insolubility. ‘Complete’ solventsfalling within the solubility area can be chosen from literature valuessuch as published in “Crowley, J. D., Teague, G. S. Jr and Lowe, J. W.Jr., Journal of Paint Technology, 1966, 38 (496), 296”. Solvent blendsmay also be used and can be identified as described in “Solvents, W. H.Ellis, Federation of Societies for Coatings Technology, p 9-10, 1986”.Such a procedure may lead to a blend of ‘non’ solvents that willdissolve both the polymers of the present invention, although it isdesirable to have at least one true solvent in a blend.

The compounds and polymers according to the present invention can alsobe used in patterned OSC layers in the devices as described above andbelow. For applications in modern microelectronics it is generallydesirable to generate small structures or patterns to reduce cost (moredevices/unit area), and power consumption. Patterning of thin layerscomprising a polymer according to the present invention can be carriedout for example by photolithography, electron beam lithography or laserpatterning.

For use as thin layers in electronic or electrooptical devices thecompounds, polymers, polymer blends or formulations of the presentinvention may be deposited by any suitable method. Liquid coating ofdevices is more desirable than vacuum deposition techniques. Solutiondeposition methods are especially preferred. The formulations of thepresent invention enable the use of a number of liquid coatingtechniques. Preferred deposition techniques include, without limitation,dip coating, spin coating, ink jet printing, nozzle printing,letter-press printing, screen printing, gravure printing, doctor bladecoating, roller printing, reverse-roller printing, offset lithographyprinting, dry offset lithography printing, flexographic printing, webprinting, spray coating, curtain coating, brush coating, slot dyecoating or pad printing.

Ink jet printing is particularly preferred when high resolution layersand devices needs to be prepared. Selected formulations of the presentinvention may be applied to prefabricated device substrates by ink jetprinting or microdispensing. Preferably industrial piezoelectric printheads such as but not limited to those supplied by Aprion, Hitachi-Koki,InkJet Technology, On Target Technology, Picojet, Spectra, Trident, Xaarmay be used to apply the organic semiconductor layer to a substrate.Additionally semi-industrial heads such as those manufactured byBrother, Epson, Konica, Seiko Instruments Toshiba TEC or single nozzlemicrodispensers such as those produced by Microdrop and Microfab may beused.

In order to be applied by ink jet printing or microdispensing, thecompounds or polymers should be first dissolved in a suitable solvent.Solvents must fulfil the requirements stated above and must not have anydetrimental effect on the chosen print head. Additionally, solventsshould have boiling points>100° C., preferably >140° C. and morepreferably >150° C. in order to prevent operability problems caused bythe solution drying out inside the print head. Apart from the solventsmentioned above, suitable solvents include substituted andnon-substituted xylene derivatives, di-C₁₋₂-alkyl formamide, substitutedand non-substituted anisoles and other phenol-ether derivatives,substituted heterocycles such as substituted pyridines, pyrazines,pyrimidines, pyrrolidinones, substituted and non-substitutedN,N-di-C₁₋₂-alkylanilines and other fluorinated or chlorinatedaromatics.

A preferred solvent for depositing a compound or polymer according tothe present invention by ink jet printing comprises a benzene derivativewhich has a benzene ring substituted by one or more substituents whereinthe total number of carbon atoms among the one or more substituents isat least three. For example, the benzene derivative may be substitutedwith a propyl group or three methyl groups, in either case there beingat least three carbon atoms in total. Such a solvent enables an ink jetfluid to be formed comprising the solvent with the compound or polymer,which reduces or prevents clogging of the jets and separation of thecomponents during spraying. The solvent(s) may include those selectedfrom the following list of examples: dodecylbenzene,1-methyl-4-tert-butylbenzene, terpineol, limonene, isodurene,terpinolene, cymene, diethylbenzene. The solvent may be a solventmixture, that is a combination of two or more solvents, each solventpreferably having a boiling point>100° C., more preferably >140° C. Suchsolvent(s) also enhance film formation in the layer deposited and reducedefects in the layer.

The ink jet fluid (that is mixture of solvent, binder and semiconductingcompound) preferably has a viscosity at 20° C. of 1-100 mPa·s, morepreferably 1-50 mPa·s and most preferably 1-30 mPa·s.

The polymer blends and formulations according to the present inventioncan additionally comprise one or more further components or additivesselected for example from surface-active compounds, lubricating agents,wetting agents, dispersing agents, hydrophobing agents, adhesive agents,flow improvers, defoaming agents, deaerators, diluents which may bereactive or non-reactive, auxiliaries, nanoparticles, colourants, dyesor pigments, furthermore, especially in case crosslinkable binders areused, catalysts, sensitizers, stabilizers, inhibitors, chain-transferagents or co-reacting monomers.

The compounds and polymers to the present invention are useful as chargetransport, semiconducting, electrically conducting, photoconducting orlight emitting materials in optical, electrooptical, electronic,electroluminescent or photoluminescent components or devices. In thesedevices, the polymers of the present invention are typically applied asthin layers or films.

Thus, the present invention also provides the use of the semiconductingcompound, polymer, polymers blend, formulation or layer in an electronicdevice. The formulation may be used as a high mobility semiconductingmaterial in various devices and apparatus. The formulation may be used,for example, in the form of a semiconducting layer or film. Accordingly,in another aspect, the present invention provides a semiconducting layerfor use in an electronic device, the layer comprising a compound,polymer, polymer blend or formulation according to the invention. Thelayer or film may be less than about 30 microns. For various electronicdevice applications, the thickness may be less than about 1 micronthick. The layer may be deposited, for example on a part of anelectronic device, by any of the aforementioned solution coating orprinting techniques.

The invention additionally provides an electronic device comprising acompound, polymer, polymer blend, formulation or organic semiconductinglayer according to the present invention. Especially preferred devicesare OFETs, TFTs, ICs, logic circuits, capacitors, RFID tags, OLEDs,OLETs, OPEDs, OPVs, OPDs, solar cells, laser diodes, photoconductors,photodetectors, electrophotographic devices, electrophotographicrecording devices, organic memory devices, sensor devices, chargeinjection layers, Schottky diodes, planarising layers, antistatic films,conducting substrates and conducting patterns.

Especially preferred electronic device are OFETs, OLEDs and OPV devices,in particular bulk heterojunction (BHJ) OPV devices and OPD devices. Inan OFET, for example, the active semiconductor channel between the drainand source may comprise the layer of the invention. As another example,in an OLED device, the charge (hole or electron) injection or transportlayer may comprise the layer of the invention.

For use in OPV or OPD devices the polymer according to the presentinvention is preferably used in a formulation that comprises orcontains, more preferably consists essentially of, very preferablyexclusively of, a p-type (electron donor) semiconductor and an n-type(electron acceptor) semiconductor. The p-type semiconductor isconstituted by a polymer according to the present invention. The n-typesemiconductor can be an inorganic material such as zinc oxide (ZnO_(x)),zinc tin oxide (ZTO), titan oxide (TiO_(x)), molybdenum oxide (MoO_(x)),nickel oxide (NiO_(x)), or cadmium selenide (CdSe), or an organicmaterial such as graphene or a fullerene or substituted fullerene, forexample an indene-C₆₀-fullerene bisaduct like ICBA, or a(6,6)-phenyl-butyric acid methyl ester derivatized methano C₆₀fullerene, also known as “PCBM-C₆₀” or “C₆₀PCBM”, as disclosed forexample in G. Yu, J. Gao, J. C. Hummelen, F. Wudl, A. J. Heeger, Science1995, Vol. 270, p. 1789 ff and having the structure shown below, orstructural analogous compounds with e.g. a C₆₁ fullerene group, a C₇₀fullerene group, or a C₇₁ fullerene group, or an organic polymer (seefor example Coakley, K. M. and McGehee, M. D. Chem. Mater. 2004, 16,4533).

Preferably the polymer according to the present invention is blendedwith an n-type semiconductor such as a fullerene or substitutedfullerene, like for example PCBM-C₆₀, PCBM-C₇₀, PCBM-C₆₁, PCBM-C₇₁,bis-PCBM-C₆₁, bis-PCBM-C₇₁, ICBA(1′,1″,4′,4″-tetrahydro-di[1,4]methanonaphthaleno[1,2:2′,3′;56,60:2″,3″][5,6]fullerene-C60-lh),graphene, or a metal oxide, like for example, ZnO_(x), TiO_(x), ZTO,MoO_(x), NiO_(x), to form the active layer in an OPV or OPD device. Thedevice preferably further comprises a first transparent orsemi-transparent electrode on a transparent or semi-transparentsubstrate on one side of the active layer, and a second metallic orsemi-transparent electrode on the other side of the active layer.Further preferably the OPV or OPD device comprises, between the activelayer and the first or second electrode, one or more additional bufferlayers acting as hole transporting layer and/or electron blocking layer,which comprise a material such as metal oxide, like for example, ZTO,MoO_(x), NiO_(x), a conjugated polymer electrolyte, like for examplePEDOT:PSS, a conjugated polymer, like for example polytriarylamine(PTAA), an organic compound, like for exampleN,N′-diphenyl-N,N′-bis(1-naphthyl)(1,1′-biphenyl)-4,4′diamine (NPB),N,N′-diphenyl-N,N′-(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine (TPD), oralternatively as hole blocking layer and/or electron transporting layer,which comprise a material such as metal oxide, like for example,ZnO_(x), TiO_(x), a salt, like for example LiF, NaF, CsF, a conjugatedpolymer electrolyte, like for examplepoly[3-(6-trimethylammoniumhexyl)thiophene],poly(9,9-bis(2-ethylhexyl)-fluorene]-b-poly[3-(6-trimethylammoniumhexyl)thiophene],orpoly[(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)]or an organic compound, like for exampletris(8-quinolinolato)-aluminium(III) (Alq₃),4,7-diphenyl-1,10-phenanthroline.

In a blend or mixture of a polymer according to the present inventionwith a fullerene or modified fullerene, the ratio polymer:fullerene ispreferably from 5:1 to 1:5 by weight, more preferably from 1:1 to 1:3 byweight, most preferably 1:1 to 1:2 by weight. A polymeric binder mayalso be included, from 5 to 95% by weight. Examples of binder includepolystyrene (PS), polypropylene (PP) and polymethylmethacrylate (PMMA).

To produce thin layers in BHJ OPV devices the compounds, polymers,polymer blends or formulations of the present invention may be depositedby any suitable method. Liquid coating of devices is more desirable thanvacuum deposition techniques. Solution deposition methods are especiallypreferred. The formulations of the present invention enable the use of anumber of liquid coating techniques. Preferred deposition techniquesinclude, without limitation, dip coating, spin coating, ink jetprinting, nozzle printing, letter-press printing, screen printing,gravure printing, doctor blade coating, roller printing, reverse-rollerprinting, offset lithography printing, dry offset lithography printing,flexographic printing, web printing, spray coating, dip coating, curtaincoating, brush coating, slot dye coating or pad printing. For thefabrication of OPV devices and modules area printing method compatiblewith flexible substrates are preferred, for example slot dye coating,spray coating and the like.

Suitable solutions or formulations containing the blend or mixture of apolymer according to the present invention with a C₆₀ or C₇₀ fullereneor modified fullerene like PCBM must be prepared. In the preparation offormulations, suitable solvent must be selected to ensure fulldissolution of both component, p-type and n-type and take into accountthe boundary conditions (for example rheological properties) introducedby the chosen printing method.

Organic solvent are generally used for this purpose. Typical solventscan be aromatic solvents, halogenated solvents or chlorinated solvents,including chlorinated aromatic solvents. Examples include, but are notlimited to chlorobenzene, 1,2-dichlorobenzene, chloroform,1,2-dichloroethane, dichloromethane, carbon tetrachloride, toluene,cyclohexanone, ethylacetate, tetrahydrofuran, anisole, morpholine,o-xylene, m-xylene, p-xylene, 1,4-dioxane, acetone, methylethylketone,1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane,ethyl acetate, n-butyl acetate, dimethylformamide, dimethylacetamide,dimethylsulfoxide, tetraline, decaline, indane, methyl benzoate, ethylbenzoate, mesitylene and combinations thereof.

The OPV device can for example be of any type known from the literature(see e.g. Waldauf et al., Appl. Phys. Lett., 2006, 89, 233517).

A first preferred OPV device according to the invention comprises thefollowing layers (in the sequence from bottom to top):

-   -   optionally a substrate,    -   a high work function electrode, preferably comprising a metal        oxide, like for example ITO, serving as anode,    -   an optional conducting polymer layer or hole transport layer,        preferably comprising an organic polymer or polymer blend, for        example of PEDOT:PSS (poly(3,4-ethylenedioxythiophene):        poly(styrene-sulfonate), or TBD        (N,N′-dyphenyl-N—N′-bis(3-methylphenyl)-1,1′biphenyl-4,4′-diamine)        or NBD        (N,N′-dyphenyl-N—N′-bis(1-napthylphenyl)-1,1′biphenyl-4,4′-diamine),    -   a layer, also referred to as “active layer”, comprising a p-type        and an n-type organic semiconductor, which can exist for example        as a p-type/n-type bilayer or as distinct p-type and n-type        layers, or as blend or p-type and n-type semiconductor, forming        a BHJ,    -   optionally a layer having electron transport properties, for        example comprising LiF,    -   a low work function electrode, preferably comprising a metal        like for example aluminum, serving as cathode,    -   wherein at least one of the electrodes, preferably the anode, is        transparent to visible light, and    -   wherein the p-type semiconductor is a polymer according to the        present invention.

A second preferred OPV device according to the invention is an invertedOPV device and comprises the following layers (in the sequence frombottom to top):

-   -   optionally a substrate,    -   a high work function metal or metal oxide electrode, comprising        for example ITO, serving as cathode,    -   a layer having hole blocking properties, preferably comprising a        metal oxide like TiO_(x) or Zn_(x),    -   an active layer comprising a p-type and an n-type organic        semiconductor, situated between the electrodes, which can exist        for example as a p-type/n-type bilayer or as distinct p-type and        n-type layers, or as blend or p-type and n-type semiconductor,        forming a BHJ,    -   an optional conducting polymer layer or hole transport layer,        preferably comprising an organic polymer or polymer blend, for        example of PEDOT:PSS or TBD or NBD,    -   an electrode comprising a high work function metal like for        example silver, serving as anode,    -   wherein at least one of the electrodes, preferably the cathode,        is transparent to visible light, and    -   wherein the p-type semiconductor is a polymer according to the        present invention.

In the OPV devices of the present invention the p-type and n-typesemiconductor materials are preferably selected from the materials, likethe polymer/fullerene systems, as described above.

When the active layer is deposited on the substrate, it forms a BHJ thatphase separates at nanoscale level. For discussion on nanoscale phaseseparation see Dennler et al, Proceedings of the IEEE, 2005, 93 (8),1429 or Hoppe et al, Adv. Func. Mater, 2004, 14(10), 1005. An optionalannealing step may be then necessary to optimize blend morphology andconsequently OPV device performance.

Another method to optimize device performance is to prepare formulationsfor the fabrication of OPV(BHJ) devices that may include high boilingpoint additives to promote phase separation in the right way.1,8-Octanedithiol, 1,8-diiodooctane, nitrobenzene, chloronaphthalene,and other additives have been used to obtain high-efficiency solarcells. Examples are disclosed in J. Peet, et al, Nat. Mater., 2007, 6,497 or Fréchet et al. J. Am. Chem. Soc., 2010, 132, 7595-7597.

The compounds, polymers, formulations and layers of the presentinvention are also suitable for use in an OFET as the semiconductingchannel. Accordingly, the invention also provides an OFET comprising agate electrode, an insulating (or gate insulator) layer, a sourceelectrode, a drain electrode and an organic semiconducting channelconnecting the source and drain electrodes, wherein the organicsemiconducting channel comprises a compound, polymer, polymer blend,formulation or organic semiconducting layer according to the presentinvention. Other features of the OFET are well known to those skilled inthe art.

OFETs where an OSC material is arranged as a thin film between a gatedielectric and a drain and a source electrode, are generally known, andare described for example in U.S. Pat. No. 5,892,244, U.S. Pat. No.5,998,804, U.S. Pat. No. 6,723,394 and in the references cited in thebackground section. Due to the advantages, like low cost productionusing the solubility properties of the compounds according to theinvention and thus the processibility of large surfaces, preferredapplications of these FETs are such as integrated circuitry, TFTdisplays and security applications.

The gate, source and drain electrodes and the insulating andsemiconducting layer in the OFET device may be arranged in any sequence,provided that the source and drain electrode are separated from the gateelectrode by the insulating layer, the gate electrode and thesemiconductor layer both contact the insulating layer, and the sourceelectrode and the drain electrode both contact the semiconducting layer.

An OFET device according to the present invention preferably comprises:

-   -   a source electrode,    -   a drain electrode,    -   a gate electrode,    -   a semiconducting layer,    -   one or more gate insulator layers,    -   optionally a substrate.        wherein the semiconductor layer preferably comprises a compound,        polymer, polymer blend or formulation as described above and        below.

The OFET device can be a top gate device or a bottom gate device.Suitable structures and manufacturing methods of an OFET device areknown to the skilled in the art and are described in the literature, forexample in US 2007/0102696 A1.

The gate insulator layer preferably comprises a fluoropolymer, like e.g.the commercially available Cytop 809M® or Cytop 107M® (from AsahiGlass). Preferably the gate insulator layer is deposited, e.g. byspin-coating, doctor blading, wire bar coating, spray or dip coating orother known methods, from a formulation comprising an insulator materialand one or more solvents with one or more fluoro atoms (fluorosolvents),preferably a perfluorosolvent. A suitable perfluorosolvent is e.g. FC75®(available from Acros, catalogue number 12380). Other suitablefluoropolymers and fluorosolvents are known in prior art, like forexample the perfluoropolymers Teflon AF® 1600 or 2400 (from DuPont) orFluoropel® (from Cytonix) or the perfluorosolvent FC 43® (Acros, No.12377). Especially preferred are organic dielectric materials having alow permittivity (or dielectric constant) from 1.0 to 5.0, verypreferably from 1.8 to 4.0 (“low k materials”), as disclosed for examplein US 2007/0102696 A1 or U.S. Pat. No. 7,095,044.

In security applications, OFETs and other devices with semiconductingmaterials according to the present invention, like transistors ordiodes, can be used for RFID tags or security markings to authenticateand prevent counterfeiting of documents of value like banknotes, creditcards or ID cards, national ID documents, licenses or any product withmonetry value, like stamps, tickets, shares, cheques etc.

Alternatively, the materials according to the invention can be used inOLEDs, e.g. as the active display material in a flat panel displayapplications, or as backlight of a flat panel display like e.g. a liquidcrystal display. Common OLEDs are realized using multilayer structures.An emission layer is generally sandwiched between one or moreelectron-transport and/or hole-transport layers. By applying an electricvoltage electrons and holes as charge carriers move towards the emissionlayer where their recombination leads to the excitation and henceluminescence of the lumophor units contained in the emission layer. Theinventive compounds, materials and films may be employed in one or moreof the charge transport layers and/or in the emission layer,corresponding to their electrical and/or optical properties. Furthermoretheir use within the emission layer is especially advantageous, if thecompounds, materials and films according to the invention showelectroluminescent properties themselves or comprise electroluminescentgroups or compounds. The selection, characterization as well as theprocessing of suitable monomeric, oligomeric and polymeric compounds ormaterials for the use in OLEDs is generally known by a person skilled inthe art, see, e.g., Müller et al, Synth. Metals, 2000, 111-112, 31-34,Alcala, J. Appl. Phys., 2000, 88, 7124-7128 and the literature citedtherein.

According to another use, the materials according to this invention,especially those showing photoluminescent properties, may be employed asmaterials of light sources, e.g. in display devices, as described in EP0 889 350 A1 or by C. Weder et al., Science, 1998, 279, 835-837.

A further aspect of the invention relates to both the oxidised andreduced form of the compounds according to this invention. Either lossor gain of electrons results in formation of a highly delocalised ionicform, which is of high conductivity. This can occur on exposure tocommon dopants. Suitable dopants and methods of doping are known tothose skilled in the art, e.g. from EP 0 528 662, U.S. Pat. No.5,198,153 or WO 96/21659.

The doping process typically implies treatment of the semiconductormaterial with an oxidating or reducing agent in a redox reaction to formdelocalised ionic centres in the material, with the correspondingcounterions derived from the applied dopants. Suitable doping methodscomprise for example exposure to a doping vapor in the atmosphericpressure or at a reduced pressure, electrochemical doping in a solutioncontaining a dopant, bringing a dopant into contact with thesemiconductor material to be thermally diffused, and ion-implantation ofthe dopant into the semiconductor material.

When electrons are used as carriers, suitable dopants are for examplehalogens (e.g., I₂, Cl₂, Br₂, ICl, ICl₃, IBr and IF), Lewis acids (e.g.,PF₅, AsF₅, SbF₅, BF₃, BCl₃, SbCl₅, BBr₃ and SO₃), protonic acids,organic acids, or amino acids (e.g., HF, HCl, HNO₃, H₂SO₄, HClO₄, FSO₃Hand ClSO₃H), transition metal compounds (e.g., FeCl₃, FeOCl, Fe(ClO₄)₃,Fe(4-CH₃C₆H₄SO₃)₃, TiCl₄, ZrCl₄, HfCl₄, NbF₅, NbCl₅, TaCl₅, MoF₅, MoCl₅,WF₅, WCl₆, UF₆ and LnCl₃ (wherein Ln is a lanthanoid), anions (e.g.,Cl⁻, Br⁻, I⁻, I₃ ⁻, HSO₄ ⁻, SO₄ ²⁻, NO₃ ⁻, ClO₄ ⁻, BF₄ ⁻, PF₆ ⁻, AsF₆ ⁻,SbF₆ ⁻, FeCl₄ ⁻, Fe(CN)₆ ³⁻, and anions of various sulfonic acids, suchas aryl-SO₃ ⁻). When holes are used as carriers, examples of dopants arecations (e.g., H⁺, Li⁺, Na⁺, K⁺, Rb⁺ and Cs⁺), alkali metals (e.g., Li,Na, K, Rb, and Cs), alkaline-earth metals (e.g., Ca, Sr, and Ba), O₂,XeOF₄, (NO₂ ⁺)(SbF₆ ⁻), (NO₂ ⁺)(SbCl₆ ⁻), (NO₂ ⁺)(BF₄ ⁻), AgClO₄,H₂IrCl₆, La(NO₃)₃.6H₂O, FSO₂OOSO₂F, Eu, acetylcholine, R₄N⁺, (R is analkyl group), R₄P⁺ (R is an alkyl group), R₆As⁺ (R is an alkyl group),and R₃S⁺ (R is an alkyl group).

The conducting form of the compounds of the present invention can beused as an organic “metal” in applications including, but not limitedto, charge injection layers and ITO planarising layers in OLEDapplications, films for flat panel displays and touch screens,antistatic films, printed conductive substrates, patterns or tracts inelectronic applications such as printed circuit boards and condensers.

The compounds and formulations according to the present invention mayalso be suitable for use in organic plasmon-emitting diodes (OPEDs), asdescribed for example in Koller et al., Nat. Photonics, 2008, 2, 684.

According to another use, the materials according to the presentinvention can be used alone or together with other materials in or asalignment layers in LCD or OLED devices, as described for example in US2003/0021913. The use of charge transport compounds according to thepresent invention can increase the electrical conductivity of thealignment layer. When used in an LCD, this increased electricalconductivity can reduce adverse residual dc effects in the switchableLCD cell and suppress image sticking or, for example in ferroelectricLCDs, reduce the residual charge produced by the switching of thespontaneous polarisation charge of the ferroelectric LCs. When used inan OLED device comprising a light emitting material provided onto thealignment layer, this increased electrical conductivity can enhance theelectroluminescence of the light emitting material. The compounds ormaterials according to the present invention having mesogenic or liquidcrystalline properties can form oriented anisotropic films as describedabove, which are especially useful as alignment layers to induce orenhance alignment in a liquid crystal medium provided onto saidanisotropic film. The materials according to the present invention mayalso be combined with photoisomerisable compounds and/or chromophoresfor use in or as photoalignment layers, as described in US 2003/0021913A1.

According to another use the materials according to the presentinvention, especially their water-soluble derivatives (for example withpolar or ionic side groups) or ionically doped forms, can be employed aschemical sensors or materials for detecting and discriminating DNAsequences. Such uses are described for example in L. Chen, D. W.McBranch, H. Wang, R. Helgeson, F. Wudl and D. G. Whitten, Proc. Natl.Acad. Sci. U.S.A., 1999, 96, 12287; D. Wang, X. Gong, P. S. Heeger, F.Rininsland, G. C. Bazan and A. J. Heeger, Proc. Natl. Acad. Sci. U.S.A.,2002, 99, 49; N. DiCesare, M. R. Pinot, K. S. Schanze and J. R.Lakowicz, Langmuir, 2002, 18, 7785; D. T. McQuade, A. E. Pullen, T. M.Swager, Chem. Rev., 2000, 100, 2537.

Unless the context clearly indicates otherwise, as used herein pluralforms of the terms herein are to be construed as including the singularform and vice versa.

Throughout the description and claims of this specification, the words“comprise” and “contain” and variations of the words, for example“comprising” and “comprises”, mean “including but not limited to”, andare not intended to (and do not) exclude other components.

It will be appreciated that variations to the foregoing embodiments ofthe invention can be made while still falling within the scope of theinvention. Each feature disclosed in this specification, unless statedotherwise, may be replaced by alternative features serving the same,equivalent or similar purpose. Thus, unless stated otherwise, eachfeature disclosed is one example only of a generic series of equivalentor similar features.

All of the features disclosed in this specification may be combined inany combination, except combinations where at least some of suchfeatures and/or steps are mutually exclusive. In particular, thepreferred features of the invention are applicable to all aspects of theinvention and may be used in any combination. Likewise, featuresdescribed in non-essential combinations may be used separately (not incombination).

Above and below, unless stated otherwise percentages are percent byweight and temperatures are given in degrees Celsius. The values of thedielectric constant c (“permittivity”) refer to values taken at 20° C.and 1,000 Hz.

The invention will now be described in more detail by reference to thefollowing examples, which are illustrative only and do not limit thescope of the invention.

EXAMPLE 1 Diethyl2,5-bis(dithieno[3,2-b;2′,3′-d]thiophen-2-yl)terephthalate (3)

A solution of dithieno[3,2-b;2′,3′-d]thiophene (5.399 g; 27.50 mmol) indry THF (75 cm³) was cooled to −78° C. and n-BuLi (11.0 cm³; 27.5 mmol)was added over 10 min. The mixture was stirred at the low temp for 3hours to yield a yellow suspension. Tributyltin chloride (7.9 cm³; 27.50mmol) was syringed into the solution in one portion and the mixture wasstirred with the cooling bath for 10 min then at rt for 3 hours to yielda clear yellow solution. The solution was evaporated to dryness byvacuum evaporation to yield a yellow oil.

A solid of diethyl 2,5-Dibromo-terephthalate (4.75 g; 12.50 mmol, thePd(II)(PPh₃)₂Cl₂ (527.9 mg; 0.75 mmol) and dry DMF (50.0 cm³) were addedsequentially and the mixture was heated to 100° C. for 15 hours to yielda green-brown suspension. Ethanol (100 cm³) was added and theprecipitated was suction filtered off and filter cake was washed withethanol, then air-dried on the filter to yield the crude product asdeep-yellow crystals. The solid was purified by flash columnedchromatography on silica eluted with chloroform to yield the pureproduct as a canary yellow powdery solid (4.667 g, 61%). ¹H-NMR (CDCl₃,300 MHz): δ=1.17 (t, J=7.2 Hz, 3H), 4.27 (q, J=7.2 Hz, 2H), 7.32 (d,J=5.3 Hz, 1H), 7.33 (s, 1H), 7.41 (d, J=5.3 Hz, 1H), 7.92 (s, 1H).

Diethyl2,5-bis(6-trimethylsilyldithieno[3,2-b;2′,3′-d]thiophen-2-yl)terephthalate

A solution of dithieno[3,2-b;2′,3′-d]thiophene (1.963 g; 10.00 mmol) inTHF anhydrous (30 cm³) was cooled to −78° C. and n-BuLi (4.2 cm³; 10.50mmol) was added over 5 min. The mixture was stirred at the low temp for3 hours to yield a thick yellow suspension. Chlorotrimethylsilane (1.60cm³; 12.61 mmol) was syringed into the solution in one portion and themixture was stirred with the cooling bath for 10 minutes then at 22° C.for 1 hour to yield a clear yellow solution.

The solution was evaporated to dryness by vacuum evaporation to yield agreenish yellow oil residue. The mixture was directly purified by flashcolumn chromatography on silica eluted with petroleum ether (40-60) toyield a colourless oil (2.367 g, 88%). ¹H-NMR (CDCl₃, 300 MHz); δ=0.20(s, 9H), 7.13 (d, J=5.3 Hz, 1H), 7.22 (s, 1H), 7.22 (d, J=5.3 Hz). GCMS:m/e 268 (M⁺).

A solution of 2-trimethylsilyldithieno[3,2-b;2′,3′-d]thiophene (2.35 g;8.75 mmol) in dry THF (25 cm³) was cooled to −78° C. and n-BuLi (3.85cm³; 9.61 mmol) was added over 10 min. The mixture was stirred at thelow temp for 2 hours to yield a yellow milky solution. Tributyltinchloride (3.1 cm³; 10.86 mmol) was syringed into the solution in oneportion and the mixture was stirred with the cooling bath for 10 minthen at rt for 1 hours to yield a clear yellow solution. The solutionwas evaporated to dryness by vacuum evaporation. The residual wasdissolved in petroleum ether (40-60) and the solution was suctionfiltered through a fiber glass filter. The filtrated was evaporatedunder vacuum to dryness to yield a deep yellow oil. A solid of diethyl2,5-Dibromo-terephthalate (1.52 g; 4.00 mmol, Pd(II)(PPh₃)₂O₂ (168.9 mg;0.24 mmol) and dry DMF (25 cm³) were added sequentially and the mixturewas heated to 100° C. for 15 hours to yield a yellow-brown suspension.The solution was vacuum evaporated to dryness to yield a dark yellowsolid. The solid was dissolved in cyclohexane and flash-columned onsilica, eluted firstly with cyclohexane to remove the yellow fraction inthe front. The eluent was than changed to chloroform to wash the secondyellow fraction down. The 2nd fraction was concentrated to nearlydryness then crashed with methanol. The precipitate was collected bysuction filtration, washed with methanol then air-dried on the filter toyield the product as deep-yellow crystals (2.09 g, 69%). ¹H-NMR (CDCl₃,300 MHz): δ=0.20 (s, 9H), 0.97 (t, J=7.1 Hz, 3H), 4.07 (q, J=7.1 Hz,2H), 7.15 (s, 1H), 7.23 (s, 1H), 7.73 (s, 1H).

Intermediate (C₁₂-IDDTT)

To a clear solution of 1-Bromo-4-dodecylbenzene (5.0 g; 15.0 mmol) indry THF (75 cm³) at −55° C. (external) was added n-BuLi (6.0 cm³; 15.0mmol) over 10 min. The mixture turned gradually into a milky whitesolution. The solution was stirred at −55° C. for 2 hours. The yellowsolid of the diethyl terephthalate 3 (1.83 g; 3.00 mmol) was added inone portion and the suspension was stirred with the cooling bath for 4hours and the temperature was allowed to rise to rt naturally over 15hours to yield a brown solution.

Dilute NH₄Cl solution (50 cm³) was added and the mixture was stirred atrt for 30 min. The upper orange-red organic layer was separated. Thelower aqueous phase was extracted with DCM (50 cm³) once and thecombined organic solution was evaporated to dryness to yield a red oil.Methanol (100 cm³) was added and the oil was triturated till itsolidified. The red-orange solid was suction filtered off and washedwell with methanol then air-dried on the filter to yield the crude diol3.47 g.

The diol was dissolved in DCM 100 cm³. p-Toluenesulphonic acidmonohydrate (0.63 g, 3.28 mmol) was added as solid in one portion. Thesolution was stirred at rt for 30 min to yield a brown solution.Triethylamine (2 cm³) was added to quench the reaction and the mixturewas vacuum evaporated to dryness. Methanol (50 cm³) was added to theresidue and the brown solid precipitate was collected by suctionfiltration and washed with methanol. The solid was then extracted withcyclohexane using a Soxhlet apparatus till no product coming down(monitored by TLC). The pale-brown solution was concentrated in vacuothen flash-columned on silica eluted with cyclohexane to yield a yellowsticky solid. The solid was crystallised from cyclohexane-ethanol toyield the product as yellow crystals (0.498 g, 11.3%). ¹H-NMR (CDCl₃,300 MHz): δ=0.87 (t, J=6.8 Hz, 6H), 1.24 (m, 36H), 1.58 (m, 4H), 2.55(t, J=7.8 Hz, 4H), 7.10 (d, J=8.3 Hz, 4H), 7.20 (d, J=5.3 Hz, 1H), 7.22(d, J=8.3 Hz, 4H), 7.30 (d, J=5.30 Hz, 1H), 7.51 (s, 1H).

Monomer 1 (C₁₂-IDDTT-Br₂)

To a solution of intermediate 6 (C₁₂-IDDTT) (0.617 g; 0.42 mmol) inchloroform (30.0 cm³) was added acetic acid (10.0 cm³) dropwise,followed by the addition of NBS (0.166 g; 0.92 mmol) as solid in oneportion. The mixture was stirred at 22° C. for 2 hours to yield abrownish-yellow solution. The solution was concentrated on a rotaryevaporator under vacuum till a suspension was obtained. Ethanol (20 cm³)was added and the yellow solid was collected by suction filtration thenwashed with ethanol and air-dried.

The crude product was flash-columned on silica eluted with cyclohexaneto yield a green-yellow solid. The solid was further recrystallised fromcyclohexane-ethanol to yield a canary yellow solid (0.60 g, 87%). ¹H-NMR(CD₂Cl₂, 300 MHz): δ=0.92 (t, J=6.8 Hz, 6H), 1.31 (m, 36H), 1.63 (m,4H), 2.61 (t, J=7.8 Hz, 4H), 7.15 (d, J=8.4 Hz, 4H), 7.24 (d, J=8.4 Hz,4H), 7.26 (s, 1H), 7.60 (s, 1H). ¹³C-NMR (CD₂Cl₂, 75 MHz): δ=14.2, 23.0,29.69, 29.81, 29.83, 30.00, 30.02, 31.7, 32.3, 35.9, 63.6, 117.2, 123.8,128.4, 129.0, 132.4, 133.0, 135.6, 136.3, 140.1, 142.6, 142.7, 147.8.

EXAMPLE 2 Intermediate C₁₆-IDDTT

To a clear solution of 1-Bromo-4-hexadecylbenzene (1.932 g; 5.00 mmol)in dry THF (50 cm³) at −35° C. was added n-BuLi (2.0 cm³; 5.00 mmol)over 20 min. The resultant milky yellow solution was stirred at −30 to−35° C. for an additional 1 h. The solid of diethyl2,5-bis(6-trimethylsilyldithieno[3,2-b;2′,3′-d]thiophen-2-yl)terephthalate(from Example 1) (0.755 g; 1.00 mmol) was added in one portion and thesuspension was stirred with the cooling bath for 4 h before thetemperature was allowed to rise to rt naturally over 15 h to yield aclear orange solution. Water (50 cm³) was added and the mixture wasstirred for 30 min to yield a yellow two-layer mixture. The upperorganic layer was separated and the lower aqueous phase was extractedonce with diethyl ether (30 cm³).

The combined organic solution was vacuum evaporated to remove theorganic solvent. Acetonitril (50 cm³) was added to residue and thesticky yellow solid was collected by suction filtration and washed withacetonitrile then air-dried on the filter with suction.

The solid was dissolved in chloroform (40 cm³) and p-toluenesulfonicacid monohydrate (50.0 mg; 0.26 mmol) was added with stirring. The deepyellow solution was stirred at rt for 15 h to yield a brownish yellowsolution. The solvent was removed by vacuum evaporation and residue wastriturated with ethanol then suction filtered off and washed withethanol and air-dried. The solid was purified by flash columnchromatography on silica eluted with 5% dcm in cyclohexane to yield ayellow solid. The solid further purified by dissolving in chloroformthen precipitated with ethanol to yield a canary yellow solid (0.82 g,48%). ¹H NMR (CDCl₃, 300 MHz): δ=0.87 (t, J=6.7 Hz, 6H), 1.24 (m, 52H),1.58 (m, 4H), 2.55 (m, 4H), 7.09 (d, J=8.3 Hz, 4H), 7.20 (d, J=5.2 Hz,1H), 7.21 (d, J=8.3 Hz, 4H), 7.30 (d, J=5.3 Hz, 1H), 7.51 (s, 1H).

Monomer 2 (C₁₆-IDDTT-Br₂)

To a solution of C₁₆—IDDTT (0.820 g; 0.48) in chloroform (30 cm³) wasadded acetic acid (10 cm³) dropwise, followed by the addition of NBS(0.192 g; 1.07 mmol) in one portion. The mixture was stirred at 22° C.for 2 hours to yield a brownish-yellow solution. The solution wasconcentrated on a rotary evaporator till a suspension was obtained.Ethanol (20 cm³) was added and the yellow solid was collected by suctionfiltration, washed with ethanol then air-dried.

The crude yellow solid was flash-column chromatographed on silica elutedwith cyclohexane. The solid was further purified by recrystallisationfrom cyclohexane-ethanol mixture to yield the product as a canary-yellowsolid (0.76 g, 83%). ¹H-NMR (CD₂Cl₂, 300 MHz 13124.1): δ=0.87 (t, J=6.7Hz, 6H), 1.24 (m, 52H), 1.57 (m, 4H), 2.55 (m, 4H), 7.09 (d, J=8.3 Hz,4H), 7.18 (d, J=8.3 Hz, 4H), 7.19 (s, 1H), 7.50 (s, 1H)

EXAMPLE 3 Polymer P-1 (poly-C₁₂-IDDTT-co-C₈-Phen)

A Schlenk tube was charged with9,10-dioctyl-2,7-phenanthrylene-bis(1,3,2-dioxaborolane) (166.8 mg; 0.31mmol), C₁₂-IDDTT-Br₂ (Monomer 1 from Example 1) (500.0 mg; 0.31 mmol)Pd₂(dba)₃ (3.5 mg; 1.2 mol %), tri-o-tolyl-phosphane (7.5 mg; 8.0 mol %)and potassium phosphate monohydrate (0.319 g; 1.38 mmol, 450 mol %). Tothis sealed tube were also added toluene (3.0 cm³), 1,4-dioxane (3.0cm³) and HPLC-water (3.0 cm³). The deep-yellow thick suspension was thendegassed (stirred, bubbling N₂) for 1 hour.

The degassed suspension was placed in a pre-heated oil-bath of 110° C.and stirred vigorously for 1 hour 40 min. The tube was lifted from theoil-bath and was cooled briefly for 5 min. Bromobenzene (0.05 ml, 0.47mmol) was added through a syringe. The tube was placed back to theoil-bath and stirred vigorously for 50 min. The tube was lifted from thebath and cooled briefly again, followed by the addition of aphenylboronic acid (75 mg, 0.62 mmol, dissolved in 0.5 ml degassed1,4-dioxane). The mixture was heated and stirred for an additional halfan hour then cooled to rt. The thick red slurry was transferred intovigorously stirred methanol (200 cm³) and stirred for 30 min. The redsolid was collected by suction filtration and washed with methanol,water then acetone sequentially. The polymer solid was then purified bySoxhleted extraction with acetone, cyclohexane, chloroform andchlorobenzene sequentially. The chloroform fraction yielded an orangefibrous solid (77 mg). The molecular weights as determined by GPC(chlorobenzen, 50° C.) were: M_(n)=100,100; M_(w)=380,000 g/mol; Pd:=9.08. The chlorobenzene fraction afforded another batch of orangefibrous solid (156 mg), with molecular weights ofM_(n)/M_(w)=112,700/498,800, Pd=4.43 (chlorobenzen, 50° C.); and ofM_(n)/M_(w)=114,500/643,100, Pd=5.62 (1,2,4-trichlorobenzene, 140° C.).The combined yield of these two batches of solid was 41%.

EXAMPLE 4 Polymer P-2 (poly-C₁₆-IDDTT-co-BiT)

A Schlenk tube was charged with C₁₆-IDDTT-Br₂ (Monomer 2 from Example 3)(407.1 mg; 0.22 mmol), 5,5′-bis(trimethylstannyl)-2,2′-bithiophene(108.2 mg; 0.22 mmol), Pd₂(dba)₃ (2.8 mg; 0.004 mmol),tri-o-tolylphosphine (6.1 mg; 0.02 mmol), toluene, anhydrous (9.0 cm³)and DMF (1.0 cm³). The mixture was degassed by bubbling nitrogen for 1 hthen heated at 110° C. for 30 min to yield a red viscous solution.Bromo-benzene (0.05 cm³; 0.47 mmol) was added and the mixture wasstirred at 110° C. for 50 min followed by the addition of phenyltri(n-butyl)stannane (0.2 cm³; 0.62 mmol). The red solution was stirredfor an additional 50 min with heating.

The solution was slightly cooled naturally for 10 min then precipitatedinto stirred methanol and the red polymer fiber was suction filtered offand washed with methanol and acetone. The solid was purified by Soxhletextraction with acetone, petroleum ether (40-60° C.), cyclohexane andfinally with chloroform. The chloroform solution was concentrated thenprecipitated into stirred methanol. The red solid was collected bysuction filtration and washed with methanol and acetone then dried undervacuum to afford polymer P-2 as dark red solid (0.39 g, 95%). Molecularweights were determining by GPC using chlorobenzene as eluent at 50° C.,showing Mn/Mw=120,100/428,300 g/mol; Pd=3.57.

EXAMPLE 5 Polymer P-3 (poly-C₁₆-IDDTT-co-TT)

A Schlenk tube was charged with C₁₆-IDDTT-Br₂ (Monomer 2 from Example 3)(407.1 mg; 0.22 mmol), 2,5-bis(trimethylstannyl)thieno[3,2-b]thiophene(102.5 mg; 0.22 mmol), Pd₂(dba)₃ (2.8 mg; 0.004 mmol),tri-o-tolylphosphine (6.1 mg; 0.02 mmol), toluene, anhydrous (10.0 cm³)and DMF (1.0 cm³). The mixture was degassed by bubbling nitrogen for 1 hthen heated at 110° C. for 5 min to yield a red viscous solution.Chlororbenzen (5.0 cm³) and bromobenzene (0.05 cm³; 0.47 mmol) wereadded and the mixture was stirred at 110° C. for 10 min followed by theaddition of phenyl tri(n-butyl)stannane (0.2 cm³; 0.62 mmol). The redsolution was stirred for an additional 50 min with heating.

The solution was slightly cooled naturally then precipitated intostirred methanol and the deep-red polymer fiber was suction filtered offand washed with acetone. The solid was purified by Soxhlet extractionwith acetone, cyclohexane and finally with chlorobenzene (150 cm³). Thechlorobenzene solution was cooled to rt then precipitated into stirredmethanol. The red solid was collected by suction filtration and washedwith acetone then dried under vacuum to afford polymer P-3 as dark redsolid (0.363 g, 90%). Molecular weights were determining by GPC usingchlorobenzene as eluent at 50° C., showing Mn/Mw=127,800/313,100 g/mol;Pd=2.45.

EXAMPLE 6 Field-Effect Transistor Fabrication and Measurements A GeneralProcedure

Top-gate bottom contact thin-film organic field-effect transistors(OFETs) were fabricated on XG glass substrates with thermally evaporatedAu source-drain electrodes. The glass substrate was treated with Decon90 for 30 minutes, rinsed with de-ionised water four times,supersonicated in de-ionised water and methanol sequentially for 1minute each and finally spin-dried in air. The Au electrodes weredeposited under 5×10⁻⁶ mBar vacuum at a rate of 0.1-0.2 nm/s. A solutioncomprising a semiconducting polymer according to the present inventionin o-dichlorobenenzene at the concentration of 7 mg/cm³ was spin-coatedon top followed by a spin-coated fluoropolymer dielectric material(D139). Finally the Au gate electrode was deposited by thermalevaporation. The electrical characterization of the transistor deviceswas carried out in ambient air atmosphere using a computer controlledAgilent 4155C Semiconductor Parameter Analyser. Charge carriermobilities for the polymers in the saturation regime (μ_(sat))(V_(d)>(V_(g)−V₀)) were calculated using equation (1):

$\begin{matrix}{\left( \frac{\mathbb{d}I_{d}^{sat}}{\mathbb{d}V_{g}} \right)_{V_{d}} = {\frac{{WC}_{i}}{L}{\mu^{sat}\left( {V_{g} - V_{0}} \right)}}} & (1)\end{matrix}$where W is the channel width, L the channel length, C_(i) thecapacitance of insulating layer, V_(g) the gate voltage, V₀ the turn-onvoltage, and μ_(sat) is the charge carrier mobility in the saturationregime. Turn-on voltage (V₀) was determined as the onset of source-draincurrent.

The μ_(sat) for polymer P-1 from Example 3 was shown to be 0.03 cm²/Vswith I_(on)/I_(off) of 10⁴.

The invention claimed is:
 1. A polymer comprising ten or more repeating units of formula I

wherein W¹ and W² are independently of each other C(R¹R²), C═C(R¹R²), Si(R¹R²) or C═O, X¹ and X² are independently of each other S, C(R³R⁴), Si(R³R⁴), C═C(R³R⁴) or C═O, one of T¹ and T² is S and the other is CH, R¹⁻⁴ independently of each other denote H, straight-chain, branched or cyclic alkyl, with 1 to 30 C atoms, in which one or more non-adjacent CH₂ groups are optionally replaced by —O—, —S—, —C(O)—, —C(O)—O—, —O—C(O)—, —O—C(O)—O—, —CF₂—, —NR⁰—, —SiR⁰R⁰⁰—, —CHR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, Cl, Br, I or CN, or denote aryl, heteroaryl, aryloxy or heteroaryloxy with 4 to 20 ring atoms which is optionally substituted, Y¹ and Y² are independently of each other H, F, Cl or CN, and R⁰ and R⁰⁰ are independently of each other H or optionally substituted C₁₋₄₀ carbyl or hydrocarbyl, and one or more units of formula II —[(Ar¹)_(a)—(U)_(b)—(Ar²)_(c)—(Ar³)_(d)]—  II wherein U is a unit of formula I Ar¹, Ar², Ar³ are, on each occurrence identically or differently, and independently of each other, aryl or heteroaryl that is different from U, and is optionally substituted, R^(S) is on each occurrence identically or differently F, Br, Cl, —CN, —NC, —NCO, —NCS, —OCN, —SCN, —C(O)NR⁰R⁰⁰, —C(O)X⁰, —C(O)R⁰, —NH₂, —NR⁰R⁰⁰, —SH, —SR⁰, —SO₃H, —SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, optionally substituted silyl, carbyl or hydrocarbyl with 1 to 40 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, or P-Sp-, R⁰ and R⁰⁰ are independently of each other H or optionally substituted C₁₋₄₀ carbyl or hydrocarbyl, P is a polymerizable or crosslinkable group, Sp is a spacer group or a single bond, X⁰ is halogen, a, b, c are on each occurrence identically or differently 0, 1 or 2, with the proviso that b=d=1 and a=c=0, or a=b=c=d=1, or a=b=d=1 and c=0, or a=b=c=1 and d=0, or a=c=2, b=1 and d=0, or a=c=2 and b=d=1.
 2. The polymer according to claim 1, wherein in the units of formula I X¹ and X² denote S.
 3. The polymer according to claim 1, wherein the units of formula I have the following formulae:


4. The polymer according to claim 1, wherein in the units of formula I R¹⁻⁴ denote straight-chain, branched or cyclic alkyl with 1 to 30 C atoms which is unsubstituted or substituted by one or more F atoms, or denote aryl or heteroaryl that is substituted by one or more straight-chain, branched or cyclic alkyl groups with 1 to 30 C atoms, in which one or more non-adjacent CH₂ groups are optionally replaced by one or more non-adjacent CH₂ groups are optionally replaced by —O—, —S—, —C(O)—, —C(O)—O—, —O—C(O)—, —O—C(O)—O—, —NR⁰—, —SiR⁰R⁰⁰—, —CF₂—, —CHR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, Cl, Br, I or CN.
 5. The polymer according to claim 1, having a molecular weight of at least 5,000.
 6. The polymer according to claim 1, additionally comprising one or more repeating units of formula III —[(Ar¹)_(a)-(A^(c))_(b)-(Ar²)_(c)—(Ar³)_(d)]—  III wherein A^(c) is an aryl or heteroaryl group that is different from U and Ar¹⁻³, has 5 to 30 ring atoms, is optionally substituted by one or more groups R^(S), and is aryl or heteroaryl having electron acceptor properties, wherein the polymer comprises at least one repeating unit of formula III wherein b is at least
 1. 7. The polymer according to claim 1, of formula IV: *

(A)_(x)-(B)_(y)

_(n)*  IV wherein A is a unit of formula I, B is a unit that is different from A and comprises one or more aryl or heteroaryl groups that are optionally substituted, x is >0 and ≦1, Y is ≧0 and <1, x+y is 1, and n is an integer>1.
 8. The polymer according to claim 1, of the formulae *—[(Ar¹—U—Ar²)_(x)—(Ar³)_(y)]_(n)-*  IVa *—[(Ar¹—U—Ar²)_(x)—(Ar³—Ar³)_(y)]_(n)-*  IVb *—[(Ar¹—U—Ar²)_(x)—(Ar³—Ar³—Ar³)_(y)]_(n)-*  IVc —[(Ar¹)_(a)—(U)_(b)—(Ar²)_(c)—(Ar³)_(d)]_(n)—*  IVd or *—([(Ar¹)_(a)—(U)_(b)—(Ar²)_(c)—(Ar³)_(d)]_(x)—[(Ar¹)_(a)-(A^(c))_(b)-(Ar²)_(c)—(Ar³)_(d)]_(y))_(n)-*  IVe wherein A^(c) is an aryl or heteroaryl group that is different from U and Ar¹⁻³ x is >0 and ≦1, Y is ≧0 and <1, x+y is 1, and n is an integer>1, wherein these polymers can be alternating or random copolymers, and wherein in formula IVd and IVe in at least one of the repeating units [(Ar¹)_(a)—(U)_(b)—(Ar²)_(c)—(Ar³)_(d)] and in at least one of the repeating units [(Ar¹)_(a)-(A^(c))_(b)-(Ar²)_(c)—(Ar³)_(d)] b is at least
 1. 9. The polymer according to claim 7, of formula V R⁵-chain-R⁶  V wherein “chain” is a polymer chain of formulae IV, and R⁵ and R⁶ denote independently of each other H, F, Br, Cl, I, —CH₂Cl, —CHO, —CR′, CR″₂, —SiR′R″R′″, —SiR′X′X″, —SiR′R″X′, —SnR′R″R′″, —BR′R″, —B(OR′)(OR″), —B(OH)₂, —O—SO₂—R′, —CCH, —CC—SiR′₃, —ZnX′, P-Sp- or an endcap group, wherein P is a polymerizable or crosslinkable group, Sp is a spacer group or a single bond, X′ and X″ denote halogen, R′, R″ and R″ are independently of each other H or optionally substituted C₁₋₄₀ carbyl or hydrocarbyl, and two of R′, R″ and R″ may also form a ring together with the hetero atom to which they are attached.
 10. The polymer according to claim 1, wherein one or more of Ar¹, Ar² and Ar³ denote aryl or heteroaryl of the following formulae

wherein one of X¹¹ and X¹² is S and the other is Se, and R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷ and R¹⁸ independently of each other denote H or have one of the meanings of R¹.
 11. The polymer according to claim 6, wherein A^(c) and/or Ar³ denotes aryl or heteroaryl of the following formulae

wherein one of X¹¹ and X¹² is S and the other is Se, and R¹¹, R¹², R¹³, R¹⁴ and R¹⁵ independently of each other denote H or have one of the meanings of R¹.
 12. The polymer according to claim 6, wherein Ar¹ is:


13. The polymer according to claim 1, of the subformulae

wherein n is an integer>1.
 14. A mixture or polymer blend comprising one or more polymers according to claim 1 and one or more compounds or polymers having semiconducting, charge transport, hole/electron transport, hole/electron blocking, electrically conducting, photoconducting or light emitting properties.
 15. The mixture or polymer blend according to claim 14, further comprising one or more n-type organic semiconductor compounds.
 16. The mixture or polymer blend according to claim 15, wherein the n-type organic semiconductor compound is a fullerene or substituted fullerene.
 17. A formulation comprising one or more polymers, mixtures or polymer blends according to claim 1, and one or more solvents.
 18. The polymer according to claim 1, having a molecular weight of at least 10,000.
 19. A charge transport, semiconducting, electrically conducting, photoconducting or light emitting material comprising a polymer, formulation, mixture or polymer blend according to claim
 1. 20. An optical, electrooptical, electronic, electroluminescent or photoluminescent device, or a component thereof, or an assembly comprising said device, which device or component comprises a charge transport, semiconducting, electrically conducting, photoconducting or light emitting material according to claim
 19. 21. The device, component thereof, or assembly, according to claim 20, wherein the device is organic field effect transistors (OFET), thin film transistors (TFT), organic light emitting diodes (OLED), organic light emitting transistors (OLET), organic photovoltaic devices (OPV), organic photodetectors (OPD), organic solar cells, laser diodes, Schottky diodes or photoconductors, the component is charge injection layers, charge transport layers, interlayers, planarizing layers, antistatic films, polymer electrolyte membranes (PEM), conducting substrates, or conducting patterns, and the assembly is integrated circuits (IC), radio frequency identification (RFID) tags or security markings or security devices containing them, flat panel displays or backlights thereof, electrophotographic devices, electrophotographic recording devices, organic memory devices, sensor devices, biosensors or biochips.
 22. The device according to claim 21, which is an OFET, bulk heterojunction (BHJ) OPV device or inverted BHJ OPV device.
 23. The polymer according to claim 1, having a molecular weight of 10,000 to 300,000.
 24. A polymer comprising ten or more repeating units of formula I

wherein W¹ and W² are independently of each other C(R¹R²), C═C(R¹R²), Si(R¹R²) or C═O, X¹ and X² are independently of each other S, C(R³R⁴), Si(R³R⁴), C═C(R³R⁴) or C═O, one of T¹ and T² is S and the other is CH, R¹⁻⁴ independently of each other denote H, straight-chain, branched or cyclic alkyl, with 1 to 30 C atoms, in which one or more non-adjacent CH₂ groups are optionally replaced by —O—, —S—, —C(O)—, —C(O)—O—, —O—C(O)—, —O—C(O)—O—, —CF₂—, —NR⁰—, —SiR⁰R⁰⁰—, —CHR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, Cl, Br, I or CN, or denote aryl, heteroaryl, aryloxy or heteroaryloxy with 4 to 20 ring atoms which is optionally substituted, Y¹ and Y² are independently of each other H, F, Cl or CN, and R⁰ and R⁰⁰ are independently of each other H or optionally substituted C₁₋₄₀ carbyl or hydrocarbyl, and one or more units of formula II —[(Ar¹)_(a)—(U)_(b)—(Ar²)_(c)—(Ar³)_(d)]—  II wherein U is a unit of formula I Ar¹, Ar², Ar³ are, on each occurrence identically or differently, and independently of each other, aryl or heteroaryl that is different from U, and is optionally substituted, R^(S) is on each occurrence identically or differently F, Br, Cl, —CN, —NC, —NCO, —NCS, —OCN, —SCN, —C(O)NR⁰R⁰⁰, —C(O)X⁰, —C(O)R⁰, —NH₂, —NR⁰R⁰⁰, —SH, —SR⁰, —SO₃H, —SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, optionally substituted silyl, carbyl or hydrocarbyl with 1 to 40 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, or P-Sp-, R⁰ and R⁰⁰ are independently of each other H or optionally substituted C₁₋₄₀ carbyl or hydrocarbyl, P is a polymerizable or crosslinkable group, Sp is a spacer group or a single bond, X⁰ is halogen, a, b, c are on each occurrence identically or differently 0, 1 or 2, one or more repeating units of formula III —[(Ar¹)_(a)-(A^(c))_(b)-(Ar²)_(c)—(Ar³)_(d)]—  III wherein A^(c) is an aryl or heteroaryl group that is different from U and Ar¹⁻³, has 5 to 30 ring atoms, is optionally substituted by one or more groups R^(S), and is aryl or heteroaryl having electron acceptor properties, wherein the polymer comprises at least one repeating unit of formula III wherein b is at least
 1. 25. A polymer comprising ten or more repeating units of formula I

wherein W¹ and W² are independently of each other C(R¹R²), C═C(R¹R²), Si(R¹R²) or C═O, X¹ and X² are independently of each other S, C(R³R⁴), Si(R³R⁴), C═C(R³R⁴) or C═O, one of T¹ and T² is S and the other is CH, R¹⁻⁴ independently of each other denote H, straight-chain, branched or cyclic alkyl, with 1 to 30 C atoms, in which one or more non-adjacent CH₂ groups are optionally replaced by —O—, —S—, —C(O)—, —C(O)—O—, —O—C(O)—, —O—C(O)—O—, —CF₂—, —NR⁰—, —SiR⁰R⁰⁰—, —CHR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, Cl, Br, I or CN, or denote aryl, heteroaryl, aryloxy or heteroaryloxy with 4 to 20 ring atoms which is optionally substituted, Y¹ and Y² are independently of each other H, F, Cl or CN, and R⁰ and R⁰⁰ are independently of each other H or optionally substituted C₁₋₄₀ carbyl or hydrocarbyl, and one or more units of formula II —[(Ar¹)_(a)—(U)_(b)—(Ar)_(c)—(Ar³)_(d)]—  II wherein U is a unit of formula I Ar¹ is

Ar² and Ar³ are each independently optionally substituted aryl or heteroaryl different from U, and a is at least 1, R^(S) is on each occurrence identically or differently F, Br, Cl, —CN, —NC, —NCO, —NCS, —OCN, —SCN, —C(O)NR⁰R⁰⁰, —C(O)X⁰, —C(O)R⁰, —NH₂, —NR⁰R⁰⁰, —SH, —SR⁰, —SO₃H, —SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, optionally substituted silyl, carbyl or hydrocarbyl with 1 to 40 C atoms that is optionally substituted and optionally comprises one or more hetero atoms, or P-Sp-, R⁰ and R⁰⁰ are independently of each other H or optionally substituted C₁₋₄₀ carbyl or hydrocarbyl, P is a polymerizable or crosslinkable group, Sp is a spacer group or a single bond, X⁰ is halogen, a, b, c are on each occurrence identically or differently 0, 1 or
 2. 26. The polymer according to claim 25, wherein formula II is: —(U)_(x)— (IVa) or (—(U—Ar)_(n) (IVc), wherein x>0 and ≦1 and n is an integer>1. 